Addis Ababa University School of Graduate Studies

Addis Ababa University School of Graduate Studies

Environmental Science program

The distributions of parthenium weed (Parthenium hysterophorus L. Asteraceae) and

some of its socio-economic and ecological impacts in the Central Rift Valley, Adami

Tulu-Jido Kombolcha Woreda; Ethiopia

BY

Adane Kebede Gebeyehu

A thesis submitted to the School of Graduate Studies of the Addis Ababa

University in partial fulfillment of the requirements for the Degree of Master of

Science in Environmental Science

January 2008

ADDIS ABABA




A Thesis Submitted to the School of Graduate Studies of Addis Ababa

University in Partial Fulfillment of the Requirements for the Degree of

Master in Environmental Science

By


Addis Ababa University

Faculty of Science, Environmental Science Program

January 2008

ii




By


Approval of the Board of Examiners

Name Signature ______________________________________ ____________

Chairman, Department of Graduate Committee

______________________________________ _____________

______________________________________ ______________

Advisors

___________________________________ _______________

Examiner

______________________________________ _______________

Examiner

iii

DECLARATION

This thesis is my original work, has not been presented for a degree in any university and

all sources of materials used for the thesis has been gratefully acknowledged.

Adane Kebede

Signature__________________________

Date___________________________

iv

Acknowledgements

First and for most, my greatest thanks goes to my advisors Dr. Mekuria Argaw and

Dr. Mulugeta Lemenih for their close guidance, valuable criticism, advice, and support in

completion of the research and writing the thesis report.

I would like to extend my thanks to my sponsor organization Horn of Africa- Regional

Environment Center/Network (HoA-REC/N) for giving me the necessary financial support

for the study.

A special mention of thanks is extended to Adami Tulu-Jido Kombolcha Woreda

Agricultural and Rural development office, crop protection unit, Ato Girma, Ato Mingistu

and Ato Jemal (DAs) for their support in the field work.

Special thanks are also due to Ato Getachew Birhan (IBC) who with no reservation shared

me his knowledge and experience in the field of GIS and Geostatistics. And I am thankful

to Tigist Amare for helping me in entering raw data in to SPSS soft ware for further

analysis.

I am greatly indebted to my whole family for their help, care and support through out my

thesis work from beginning up to end. And also special thanks go to my sister, Mekides

Kebede, in London for her financial and moral support.

I am also thankful to all my friends and classmates whose names could not be mentioned

separately because of limitations; for their constant encouragement and cooperation.

I would like to express my gratitude to all those people who have spent their time directly

or indirectly to assist me in this work. Last but not least, special thanks to all the

department staffs and the university community for their cooperation and healthy

interaction with all my work and stay on the campus.

v

Acknowledgements……………………………………………………………………....v

List of Tables …………………………………………………………………. ……....viii

List of Figures……………………………………………………………………………ix

List of Appendices………………………………………………………………………..x

Acronyms…………………………………………………………………………….......xi

Abstract ………………………………………………………………………………...xii

1 INTRODUCTION…………………………………………………………………….1

1.1 Statement of the Problem………………………………………….........................3

1.2 Research Objectives……………………………………………………………….4

1.2.1 General Objective....................................................................................................4

1.2.2 Specific Objectives………………………………………………………………...4

2 REVIEW OF LITERATURE………………………………………………………...5

2.1 Biology and Ecology of P. hysterophorus L…….....………………........................5

2.1.1 Description………………………………………………………………………...5

2.1.2 Growth and Production……………………………………………………...........6

2.1.3 Ecology…………………………………………………………………………... 6

2.1.4 Distribution………………………………………………………………………..7

2.1.5 Parthenium Weed Status in Ethiopia………………………………………….. …8

2.2 Determinant Impacts of P. hysterophorus L.……………………...........................9

2.2.1 Effects on Crop Production…………………………………………………….....9

2.2.2 Effects on Animal Production………………………………………………........10

2.2.3 Effects on Health……………………………………………………………........11

2.2.4 Effects on Biodiversity……………………………………………………….......12

2.3 Control of P. hysterophorus L. …………………………………….....................13

2.3.1 Prevention..............................................................................................................13

2.3.2 Manual and Mechanical Control………………………………………………...14

2.3.3 Cultural Control…………………………………………………………………14

2.3.4 Chemical Control…………………………………………………………….......15

2.3.5 Biological Control.................................................................................................15

2.4 Geostatistics for spatial analysis………………………………………………. .16

3 MATERIALS AND METHODS……………………………………………………17

vi

3.1 Description of the Study Area…………………………………………………....17

3.1.1 Location……………………………………………………………………….....17

3.1.2 Topography………………………………………………………………………18

3.1.3 Vegetation and Wild Life………………………………………………………. .19

3.1.4 Geology and Soil…………………………………………………………………20

3.1.5 Climate…………………………………………………………………………...21

3.1.6 Population………………………………………………………………………..21

3.2 Methodologies…………………………………………………………………... 21

3.2.1 Vegetation survey………………………………………………………………...21

3.2.2 Sampling of biophysical data………………………………………………….....22

3.2.3 Sampling of weed specie…………………………………………………………23

3.2.4 Socioeconomic Survey…………………………………………………………...24

3.2.5 Environmental factors data……………………………………………………...24

3.2.6 Data Analysis……………………………………………………………………..25

4 RESULTS AND DISCUSSION…………………………………………………….28

4.1 Distribution of P.hysterophorus in the district…………………………………..28

4.1.1 Past distribution of P. hysterophorus L. …………………...................................28

4.1.2 Current distribution of P. hysterophorus L...........................................................31

4.1.3 Environmental factors that favor or disfavor the distribution of the species …...32

4.1.4 Infestation of P. hysterophorus L. ……………………………………. ………...35

4.1.5 Farmers’ practices to control P. hysterophorus L.………………………………39

4.2 Socio-Economic and Environmental Impacts of P. Hysterophorus L...................42

4.2.1 Effects on biodiversity …………………………………………………………...43

4.2.2 Effects on crop production ………………………………………………………49

4.2.3 Effects on animal production …………………………………………………....51

4.2.4 Effects on human health …………………………………………………………53

5 CONCLUSIONS AND RECOMMENDATIONS………………………………….54

6 REFERENCES……………………………………………………………………... 56

7 APPENDICES……………………………………………………………………….66

vii

List of Tables

Table 1 Kriging parameters for P. hysterophorus computed using variogram

analysis……………………………………………………………………….. ...27

Table 2 Results of correlations of some of the biophysical data………………………...34

Table 3 Distribution and scale of parthenium infestation in the Woreda………………..36

Table 4 Farmers view of the first appearance of the weed in the Woreda…………….…38

Table 5 Farmers view on the agents for the fast spread of parthenium in the Woreda ....39

Table 6 Farmers’ response on the type of measures to control dissemination of parthenium

weed in the Woreda…………………………………………………40

Table 7 The period in which P. hysterophorus was observed and start taking control

measure in different kebeles in the Woreda …………………………………...41

Table 8 Types of damages caused by parthenium as ranked by farmers ………………..43

Table 9 List of weed species in Adami Tulu-Jido Kombolcha ……………………….....43

Table 10 Importance value (IV) of species in different habitats in selected area………..48

Table 11 Farmers’ view on the impacts of P. hysterophorus on crop

productivity…………………………………………………………………….50

Table 12 Plants those resist the impact of P. hysterophorus…………………………….50

Table 13 Types of effects of P. hysterophorus on livestock production as perceived by

farmers…………………………………………………………………………52

viii

List of Figures

Fig. 1 Theoretical features of a variogram ………………………………………………17

Fig. 2 Map of Adami Tulu-Jido Kombolcha woreda…………………………………….18

Fig. 3 Elevation map of the sampling points in the study area ………………………….18

Fig. 4 Slope map of Adami Tulu-Jido Kombolcha………………………………………19

Fig. 5 The stand of parthenium weed (a) at road side of Ziway (b) at Edo Gojola area... 19

Fig. 6 Average mean temperatures and rain fall at Ziway, Adami Tulu and Bulbula

stations………………………………………………………………………....21

Fig. 7 Summary of flow chart that shows general methodology of the study …………..26

Fig. 8 Association between parthenium weed density with slope ………………………29

Fig. 9 Parthenium weed distribution nine years ago in the study area………………..…30

Fig. 10 Map of P. hysterophorus current density distribution...…………………………32

Fig. 11 Year of infestation of Parthenium hysterophorus as perceived by farmers…..…35

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List of Appendices

Appendix 1 Parthenium density, altitude and slope in association of GPS reading …….66

Appendix 2 Frequency of some of the weeds in the study area………………………….69

Appendix 3 Relative Frequency (RF) and Relative Density (RD) of species in different

habitats in selected sectors/areas…………………………………………...69

Appendix 4 Questionnaire for data collection to assess perceptions of farmers on the

distribution, socio-economic and environmental impacts of parthenium

weed………………………………………………………………………..70

Appendix 5 Percentage responses on the impacts of P. hysterophorus on human health.75

Appendix 6 Number of plough in which farmers practiced before sawing……………...76

Appendix 7 Parthenium hysterophorus at different growing stages…………………….76

x

List of Acronyms

CBD Convention on Biological Diversity

DAs Development Agents

ESRI Environmental Systems Research Institutes

Fig Figure

GIS Geographic Information System

GISP Global Invasive Species Programme GPS Global Positioning System

ILWIS Integrated Land and Water Information System

Km Kilo meter

IAS Invasive alien species

MA Millennium Assessment

m2 square meter

m meter

m a.s.l. meter above sea level

OK Ordinary Kriging

PAG Parthenium Action Group

RGO Regional Government of Oromia

SPSS Statistical Package for Social Science

SK Simple Kriging

UK Universal Kriging

xi

Abstract

Biological invasion by alien invasive species is now recognized as one of the major threats

to native species and ecosystems. P. hysterophorus is believed to have been introduced to

Ethiopia during the1970s along with the grain aid during the prolonged drought and/or

during the Ethio-Somalian war and by movement of construction materials. The aim of this

study was to generate knowledge for a better understanding of the distribution, socio-

economic & environmental impacts of P. hysterophorus in the Adami Tulu-Jido Woreda.

The biophysical data were collected by using systematic grid method, which is appropriate

for distribution mapping using geostatistics. The biodiversity impacts of P. hysterophorus

were investigated by assessing other plant species growing in association with P.

hysterophorus. The socio-economic impacts were studied by interviewing farmers. The

results show that P. hysterophorus was found to be the most frequent and dominant species

in road sides, grazing land and crop fields with IVs of 102%, 77.5% & 74.5% respectively.

It also has the highest frequency (19.2%). The weed is widely distributed in north-eastern

parts of the Woreda. Results also showed that from all the sample species P. hysterophorus

was found to be the most abundant in road sides (49.1%). Field survey results showed that

all the interviewed farmers were aware of P. hysterophorus, its ways of introduction into

their locality, the agents facilitating its dissemination and places where P. hysterophorus is

densely populated. Farmers are generally aware of the impacts of P. hysterophorus. The

impacts are on crop production (44%), livestock (30.6%), on human health (18.8%) and

has no any benefits attached to environment. This study revealed that P. hysterophorus has

become a major pest plant of the wasteland, road sides, wet lands, vacant sites and crop

fields and it has the potential to spread all over the Woreda. Hence it has a significant

effect on the economic development of the study area. Integration of different control

methods are therefore needed to prevent and control the danger of P. hysterophorus.

Key words: alien invasive weed species, Parthenium hysterophorus, geostatistics, Adami

Tulu-Jido, Central Rift Valley.

xii

1 INTRODUCTION

Biological invasions by non-native species constitute one of the leading threats to natural

ecosystems and biodiversity (Joshi, 2001; MA, 2006; CBD, 2005; Baillie et al., 2004). The

above authors also describe that the impacts of invasive alien species (IAS) on agriculture,

forestry, fisheries, and other human enterprises and on human health. In agricultural

system, invasive weeds affect the productive capacity of the land and increase agricultural

labour time, affecting human well being by threatening the availability of food as well as

reducing the time people have for recreation and other non-work activities, such as

participation in community events. Moreover, these non-native plant and animal species

harm or endanger native plants and animals or other aspects of biodiversity. They have

invaded almost every type of native ecosystem and caused hundreds of biological

extinctions throughout the world (Joshi, 2001; MA, 2006; CBD, 2005; Baillie et al., 2004).

One of such an invasive weed species introduced to Ethiopia in a recent past is Parthenium

hysterophorus (Taye Tessema, 2002; Tamado Tana, 2001; GISP, 2004).

Parthenium hysterophorus is a herbaceous invasive weed that is believed to be originated

in tropical America, now occurs widely in Australia and East and South Africa. Its annual

procumbent, diffused leafy herb, 0.5-2 m tall, bearing alternate, pinnatified leaves, belongs

to the family Asteraceae (Compositae) tribe Helintheae, sub-tribe Ambrosiinae (Navie et

al., 1996; Hedberg et al., 2004). IAS like parthenium weed are species that are introduced

to new geographic areas as a consequence of human activities, where they become

established and then proliferate and spread, to harm many of human welfare activities and

natural systems services (Kirby, 2003; Joshi, 2001).

The recent growth and development of world trade system has strengthened a long-

standing trend in the redistribution of IAS in general and parthenium weed in particular

(McNeely, 2001; McNeely et al., 2001; Perrings et al., 2005). The opening of new markets

or trade routes has also resulted in the introduction of new species either as the object of

trade or as the unintended consequence of trade (Enserink, 1999; Cassey et al., 2004;

Semmens et al., 2004).

1

IAS impact native species both directly for example, competing with them for resources

such as food and breeding sites as well as indirectly by altering habitat and modifying

hydrology, fire regimes, nutrient cycling and other ecosystem processes (Rejmanek et al.,

2000; IUCN/SSG/ISSG, 2000; MA, 2006; CBD, 2005). Together, these impacts are

resulting in the loss of biodiversity and dramatic changes to ecosystems, which is

confirmed by a recent global assessment that showed invasive alien species to have

affected 30% of threatened birds (but as much as 67% on islands), 11% of threatened

amphibians, and 8% of threatened mammals (Baillie et al., 2004). They also observed that

invasion of alien species across the planet is rated as being the second biggest threat to

biodiversity behind habitat loss.

Apart from their threat to biodiversity and ecosystem services, invasive species have

significant socio-economic impacts. The weed can affect crop production, animal

husbandry, human health and biodiversity (Evans, 1997a). IAS in general and P.

hysterophorus in particular, reduces the effectiveness of development investments by, for

example, choking irrigation canals, fouling industrial pipelines and threatening

hydroelectric schemes. Indeed, invasive species such as parthenium weed contribute to

social instability and economic hardship, placing constraints on sustainable development,

economic growth, poverty alleviation and food security (GISP, 2004).

Parthenium weed is thought to have been introduced to Ethiopia probably between 1974

and 1980, and it was also thought to have been introduced during 1980s when drought

induced famine triggered a massive multinational relief effort (Hedberg et al., 2004; GISP,

2004). The weed was first seen growing near food-aid distribution centers, so it is likely

that imported wheat grain was contaminated with its seeds. The weed spread rapidly, and

soon came to dominate pastures and crop fields because it has allelopathic properties,

releasing chemicals that suppress the growth and germination of neighboring plants

(Tadelle Tefera, 2002; Singh et al., 2005). Its invasion of Ethiopia has not only had a

devastating effect on crop production, but also results in grazing shortages, since the weed

2

is unpalatable to livestock; if it is mixed with fodder, it taints the meat and milk (GISP,

2004).

Parthenium weed (P. hysterophorus) invades disturbed land, including overgrazed weak

pastures and recently cleared or ploughed lands. Moreover, it will readily colonize

disturbed, bare areas along roadsides and heavily stocked areas around yards and watering

points (GISP, 2004; Huy and Seghal, 2004; Shabbir and Bajwa, 2006).

To monitor the spread of such invasive alien species (P. hysterophorus) different

technologies and techniques have been employed among which Geographic Information

System (GIS) and Geostatistics are the most widely used. A weed map is, therefore, useful

for identifying the affected area and the spatial distribution of weeds, and for providing a

control plan. Therefore, this thesis addresses the distribution of P. hysterophorus in Adami

Tulu-Jido Woreda by using GPS, GIS and Geostatistics as tools.

1.1 Statement of the problem

Even though invasive species, particularly parthenium weed, are causing severe damage to

the environment in Ethiopia, there is not much documented information about it. For

instance, their geographical distributions, rate of expansion, socio–economic and

environmental impacts are little documented in Ethiopia. One of the sites where abundant

occurrence of parthenium weed is mentioned is Central Rift Valley (CRV) of Ethiopia.

Such knowledge of distribution of the weed assists to design effective controlling

mechanisms to curb the impact being caused to the people and their livelihood.

Proper management of weed control and mapping of their spatial and temporal distribution

will enhance agricultural as well as socioeconomic development in the Woreda. There has

been limited or no effort to systematically and to analytically study the impact of P.

hysterophorus on households’ welfare in the study area. There are few researches made on

the impact of this weed in the eastern and north-eastern parts of the country such as by

Tamado Tana et al. (2002), Taye Tessema (2002) and Tadelle Tefera (2002). However, this

research work is different from the above studies in three ways. First, in the area context-

3

impact of parthenium weed differs from one location to another. Second, this research will

examine the environmental factors that determine parthenium weed distribution and the

level of its status, which was not considered in the studies mentioned above. Third, the

study will endeavor to show the distribution pattern of P. hysterophorus in the Woreda,

which was not dealt with in the above studies.

Furthermore, the socioeconomic and ecological impacts differ from place to place with

respect to different agro-ecological context, local socio-economic situations and

environmental factors that need to be studied in detail with in the selected study area.

1.2 Research Objectives

1.2.1 General objective

The general objective of this study is intended to examine the extent of socioeconomic and

ecological impacts of P. hysterophorus and to map the spatial and temporal distribution in

the Central Rift Valley of Ethiopia in general and Adami Tulu-Jido Kombolcha Woreda in

particular and hence to recommend possible tracking solutions for the betterment of the

livelihood and environment.

1.2.2 Specific objectives

To develop a distribution map for parthenium weed in the Adami Tulu-Jido

Kombolcha areas,

To assess the temporal and spatial distribution of parthenium weed in the Adami

Tulu-Jido Kombolcha areas,

To investigate environmental factors that favor or disfavor the distribution of the

species, and

To assess the socio-economic and environmental impacts of P. hysterophorus in the

Woreda.

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2 REVIEW OF LITERATURE

2.1 Biology and Ecology of Parthenium weed

2.1.1 Description

Parthenium hysterophorus L. (Asteraceae), an alien invasive species, commonly known as

parthenium weed, is an annual or short-lived ephemeral herb of central and southern

American origin that now has a wide range of distribution through out the earth (Navie et

al., 1996; Mahadevappa, 1997). Parthenium weed is an extremely prolific seed producer,

with up to 25,000 seeds (achenes) per plant but unable to reproduce vegetatively from plant

parts (Navie et al., 1996; ARMCANZ, ANZECC, 2000), and with an enormous seed bank,

estimated at 200,000 seeds per m2 (Joshi, 1991), it has the potential to be an extremely

aggressive colonizer of crops. The seeds spread by floating on still or flood water, blown

up by wind, or in mud adhering to animals, vehicles or machinery (Auld et al., 1983).

Parthenium weed, P. hysterophorus, is also known by a large number of other common

names including parthenium weed (Australia), bitter weed, carrot weed, broom-bush and

congress weed (India), false ragweed and ragweed parthenium (USA), whitetop, escobar

amarga, feverfew (Caribbean) and `Klidnole' (living alone) or `Feremsis' (sign your land)

(Ethiopia) (Navie et al., 1996; Tamado Tana et al., 2002; Taye Tessema, 2002).

It can grow up to two meters if there are favorable environmental conditions. Parthenium

weed is an aggressive colonizer of areas of poor ground cover and exposed soil such as

fallow wastelands, roadsides and overgrazed pastures (Huy and Seghal, 2004; Shabbir and

Bajwa, 2006). It does not usually become established in undisturbed vegetation or in

vigorous pastures, and there is a marked inverse relationship between existing plant cover

and Parthenium weed density (ARMCA&NZ, 2000).

5

2.1.2 Growth and Production

One of the most important biological characteristics for the success of parthenium as a

weed lies on its reproductive ability. Four or more successive cohorts of seedlings may be

produced in a season (Pandey and Dubby, 1989). Jayachandra (1971) and McFadyen

(1992) reported that flowering can be initiated as early as four weeks after seedling

emergence and plants continue to flower for extended periods (6-8 months) under favorable

conditions. Following another report, parthenium weed can germinate, grow, mature, and

set seed within 28 days (PAG, 2000). In developmental studies, using North American

plants, Lewis et al. (1988) reported that the time from initial appearance of the first flower

bud to the production of mature inflorescence and dispersal of the first achenes was found

to be about 30 days, while the time from pollination to achene maturation is only about

fourteen days.

There are conflicting reports as to whether parthenium weed is self-compatible or self-

incompatible. Lewis et al. (1988) detected 95% self-compatibility in the species. They

concluded that wind must be the major means of pollen dispersal and self-fertilisation must

account for at least some seed production. In contrary to Lewis et al. (1988), Gupta and

Chandra (1991) stated that parthenium weed appears to be entomophilous (insect

pollinated) or at most amphiphilous (pollen dispersed mainly by insects and partially by

wind), and that bees, ants, houseflies, and other dipterans frequently visited parthenium

weed flowers.

2.1.3 Ecology

Parthenium weed is an aggressive coloniser of disturbed land, able to germinate, grow and

flower over a wide range of temperatures and photoperiods (Evans, 1987). It occurs in the

humid and sub-humid tropics showing a marked preference for black, alkaline, cracking,

clay soils of high fertility, but also able to grow on wide variety of soil types from sea level

up to 1800 m a.s.l. (Evans, 1987). Areas receiving less than 500 mm of rainfall are

probably unsuitable although the weed has strong adaptive methods to tolerate both

6

moisture stress (Kohli and Rani, 1992) and saline conditions (Hegde and Patil, 1988).

Mahadevappa (1997) also noted that parthenium weed has several built-in properties and

efficient behavioral mechanisms that enable it to overcome many ecological adversities and

thus continue to survive under stress.

Soil moisture appears to be the major contributing factor to both life span and the duration

of flowering (Williams and Groves, 1980). Plant biomass production increases with

increasing temperature up to an optimum day/night temperature of 33/22°C. Seeds require

bare soil to germinate with little or no dormancy. Most seeds germinate within 2 years if

conditions are suitable, although up to 12% of buried seeds may be viable after 2 years

(Butler, 1984). However, in their study of germination ecology of parthenium weed

Tamado Tana et al. (2002) stated that viability of the seeds was greater than 50% after 26

months of burial and predicted a half-life of seeds in the soil of approximately three to four

years. This indicates the potential build-up of persistent soil seed bank and the difficulty of

its eradication. Although freshly harvested parthenium seed require light for germination, it

can germinate during any time of the year over a wide range of fluctuating (12/2–35/25°C)

temperatures provided adequate moisture is available (Tamado Tana et al., 2002).

2.1.4 Distribution

Parthenium hysterophorus L. occurs throughout the tropical and sub-tropical Americas

from Florida to southern Brazil and northern Argentina (Dale, 1981). It became the major

noxious weed for over the last 25 years in India (Mahadevappa, 1997) and Australia (Navie

et al., 1996). In addition, there are reports from Bangladesh (Mahadevappa, 1997), Israel

(Joel and Litson, 1986), Taiwan (Peng et al., 1988), China and Vietnam (Navie et al.,

1996), and Nepal (Mishra, 1991). Parthenium weed has recently reached in Africa, being

recorded in Kenya in 1975 in Nairobi herbarium records and it is now a weed in coffee

plantations (Njoroge, 1991). It is also present in Madagascar, Mozambique, South Africa,

and the Seychelles (Nath, 1988) and in Ethiopia was recorded since 1974-77 (Berhanu

G/Medhin, 1992; Fasil Reda, 1994; Frew Mekbib et al., 1996; Hedberg et al., 2004). This

7

indicates that parthenium weed has a potential of spreading and may become more

prominent in other part of the world in the near future unless measures are taken.

2.1.5 Parthenium weed status in Ethiopia

In Ethiopia, it is believed to have been introduced in 1976/77 with army vehicles from

Somalia and has become a serious weed both in arable and grazing lands (Tamado Tana et

al., 2002). But in contrast to this, Hedberg et al. (2004) reported that it was introduced into

Ethiopia around 1974. Others also believed that P. hysterophorus may have also been

spread through the provision of humanitarian emergency food aid. For example, this weed

was introduction to Africa through grain shipments for famine relief to Ethiopia (McNeely

et al., 2001). The weed was first seen in 1980s near food-aid distribution centers in

Ethiopia (GISP, 2004). However, currently, it is widely distributed in Ethiopia. In eastern

Ethiopia, Tamado Tana and Milberg (2000), and Tamado Tana (2001) reported that

parthenium weed is the second most frequent weed (54%) after Digitaria abyssinica

(63%).

In the central farmlands of East Shewa: Dukem, Bishoftu, Modjo, and Koka areas heavy

and widespread infestation occurs mostly on roadsides, wastelands, towns, villages and

gardens. One can also see parthenium weed infestation on field borders and in some fields;

parthenium weed grew in crop field during fallow period. In Ziway, Awassa and Wolkite,

parthenium weed was observed only in the town along the road and near dwelling sites

indicating its recent introduction into the area (Taye Tessema, 2002).

High infestation of parthenium weed was observed in sorghum fields around Kobo and in

sorghum, maize and tef fields around Robit, Gobie, Woldiya, and Kombolcha both during

the growing period and after harvesting time. Similarly, in East Shewa (Wolenchitti,

Wonji, Methara), Afar region (Awash, Anano, and Miesso), and West and East Hararghe,

heavy infestation of parthenium weed was observed both during fallow and cropping

seasons. Similarly in Hataye, Shewa Robit, Ambo, and Nazareth area, parthenium weed

has entered crop fields (Taye Tessema, 2002).

8

In highly infested areas from Woldiya to Alamata, the original grass and shrub vegetation

had been very open and the disturbance allowed a dense stand of parthenium weed to cover

thousands of hectares of grazing and cultivated lands. From Sirinka to Mersa and then to

Dessie, parthenium weed was present on the narrow strip along the main road for several

kilometers. Also he reported that in many Woredas of West Shewa: Shoboka, Tibe, Guder,

and Wolliso, only localized infestation of parthenium weed was observed on roadsides and

rarely in crop fields (Taye Tessema, 2002).

Taye Tessema (2002) also observed that the plant occurred in the towns, usually on

roadsides, and vacant sites and grew only at irregular intervals. The introduction in these

area is very recent, probably since 1997 for there had been no parthenium weed observed in

West Shewa region from 1995 – 1996 (Taye Tessema et al., 1998) during which intensive

qualitative and quantitative determination of weeds occurring in these areas took place.

2.2 Determinant impacts of parthenium weed

The impact of parthenium weed on agriculture was summarized by Parsons and

Cuthbertson (1992), McFadyen (1992), Navie et al. (1996), Tamado Tana et al.(2001) and

Evans (1997a). The authors also described that the weed could affect crop production,

animal production, human health, and biodiversity in its area of infestation. Moreover,

parthenium weed has a wide range and potentially lethal impact on man’s affair.

2.2.1 Effects on crop production

In India, according to Khosla and Sobti (1981), about 40% sorghum (Sorghum bicolor L.)

yield reduction due to parthenium weed was recorded. Channappagoudar et al. (1990) also

reported that the presence of parthenium weed in irrigated sorghum in India reduced grain

yields from 6.47 to 4.25 tons/ha (34.3%) and decreased grain weight by 30%. However, its

overall impact on the production system is multifaceted, both direct and indirect, thus

making it difficult to quantify losses (Evans, 1997a).

9

Other than direct competition for nutrients, water and sunlight, allelopathic effects of

parthenium weed on other plant is another important biological characteristic for the

success and its aggressiveness as a weed. In many studies water soluble phenolics (caffeic

acid, ferulic acid, vanicillic acid, anisic acid, and fumaric acid) and sesquiterpene lactones,

mainly parthenin, have been reported from the roots, stems, leaves, inflorescence, achenes

fruit and pollen of parthenium weed (Jarvis et al., 1985; Kanchan and Jayachandra, 1979,

1980a; Hedge and Patil, 1988; Pandy et al., 1993).

These chemicals have been observed to exhibit an inhibitory effect both on the

germination and growth of a wide variety of crops including pasture grasses, cereals,

vegetables, other weeds and even tree species (Evans, 1997a; Navie et al., 1996; Tadelle

Tefera, 2002). Kanchan and Jayachandra (1981) and Dayama (1986) reported that the

growth and nodulation of legumes were inhibited by parthenium weed because of the

inhibitory effect of allelochemicals on nitrogen fixing and nitrifying bacteria. Further,

parthenium weed pollen was found to reduce the chlorophyll content of leaves to which it

comes in contact with and can interfere with the pollen germination and fruit set of the

nearby species (Kanchan and Jayachandra, 1980b). Towers et al. (1977) also reported that

heavy accumulation of parthenium weed pollen on the stigmatic surface caused 40%

reduction in the grain filling of maize and predicted that the weed may still exhibit an

inhibitory influence on crops even when grown at a considerable distance.

2.2.2 Effects on animal production

According to Evans (1997a) the impact of parthenium weed on livestock production is both

direct and indirect by affecting grazing land, animal health, milk and meat quality, and

marketing of pasture seeds and grain. The occurrence of parthenium weed in grasslands

was observed to reduce the forage production in addition to making the land less fertile

(Vartak, 1968). In India, for instance, the weed can reduce the pasture carrying capacity by

up to 90% (Nath, 1988). In Australia, Chippendale and Panneta (1994) identified that

parthenium weed could completely dominate grazing land, resulting in a weed monoculture

and reduced stocking rate of up to 80%, with a net annual loss of AU$ 16.5 million.

10

Studies in India on toxicity of the weed to cattle and buffaloes have shown that a

significant amount (10 – 50%) of the weed in the diet can kill these animals within 30 days

(Narasimhan et al., 1977, 1980; More et al., 1982). Animals fed parthenium weed

developed dermatitis with pronounced skin lesions, became highly emaciated, and

eventually died due to the rupture of tissues and haemorrhages in their internal organs

(Nisar Ahmed et al., 1988). Taints of meat have been detected from sheep given a diet of

30% parthenium weed (Tudor et al., 1982) and tainting of milk has also been reported from

cows (Towers and Subba Rao, 1992).

2.2.3 Effects on health

Parthenium weed is also known to cause human health problems like asthma, bronchitis,

dermatitis, and hay fever (Anonymous, 1976; Kololgi et al., 1997; Srirama Rao et al.,

1991). It is reported that continued close contact with parthenium weed can develop

allergic eczematous contact dermatitis (AECD) while inhalation of pollen can cause

allergenic rhinitis which can develop into bronchitis or asthma if the pollen enters the

respiratory tract during mouth breathing (Evans, 1997a). P. hysterophorus is known to be

the causative agent of this reaction, and is one of the very reactive toxic classes of

compounds known as sesquiterpene lactones (Towers, 1981).

There has been an epidemic of hundreds of cases of parthenium weed dermatitis in India

and several cases have been reported from USA (Subba Rao et al., 1977; Towers, 1981). It

is also reported that there is an increasing incidence of respiratory allergies in India, with

7% of sample of Bangalore residents were affected by allergenic rhinitis due to parthenium

weed pollen, and 42% of patients suffer from nasobronchial allergy (Towers and Subba

Rao, 1992).

In Australia about 15% of individuals regularly exposed to parthenium weed developed

dermatitis, with another 7-15% developing respiratory problems (McFadyen, 1992). Tanner

and Mattocks (1987) hypothesised that parthenium weed contaminated animal feed leads to

11

tainted milk and the hepatotoxic parthenin reacts synergistically with copper in causing

Indian Childhood Cirrhosis (ICC).

2.2.4 Effects on biodiversity

Weeds can compute with indigenous plant species for resources (including, sunlight,

moisture, nutrients and even for spaces) (IUCN/SSC/ISSG, 2000). Besides, the impacts of

invasive alien species are immense, insidious, and usually irreversible and they may be as

damaging to native species and ecosystems on a global scale as the loss and degradation of

habitats (IUCN/SSC/ISSG, 2000; Shabbir and Bajwa, 2006). Furthermore, invasions may

alter hydrology, nutrient accumulation and cycling, and carbon sequestration on grasslands

(Polley et al., 1997). The global extent and rapid increase in invasive species is

homogenising the world’s flora and fauna (Mooney & Hobbs, 2000) and recognized as a

primary cause of global biodiversity loss (Czech & Krausman, 1997; Wilcove & Chen,

1998).

Parthenium hysterophorus, because of its invasive capacity and allelopathic properties, it

causes a lot of damage to natural ecosystems. It has been reported as causing a total habitat

change in native grasslands, open woodlands, riverbanks, and flood plains (McFadyen,

1992; Chippendale and Panetta, 1994). It releases allelopathic chemicals that inhibit the

germination and growth of pasture grasses, legumes, cereals, vegetables, other weeds

species and even trees in the field (Tamado Tana, 2001; Tadelle Tefera, 2000; Kohli et al.,

1985; Adkins and Sowerby, 1996).

The allelopathic potential of P. hysterophorus is believed to play an important role in the

ability of the plant to displace natural vegetation and interrupt natural succession in the

natural environments. P. hysterophorus displaces the native as well as exotic species and

also medicinal plants (Shabbir and Bajwa, 2006). They further explain that, the domination

of parthenium weed affects the biodiversity. The population of many common medicinal

plants growing in the wastelands of Islamabad might be rapidly declining because of the

aggressive colonization by P. hysterophorus (Shabbir and Bajwa, 2006).

12

2.3 Control of parthenium weed

So far, no single method of parthenium weed control has been proved satisfactory as each

method suffers from one or more limitations such as inefficiency, high cost,

impracticability, environmental safety and only temporary relief (Bhan et al., 1997;

Mahadevappa, 1997). Hence, there is an urgent need to adopt an integrated parthenium

weed management approach by amalgamating more than one option. The components of

integrated management such as prevention, manual, mechanical, cultural, chemical and

biological control measures are briefed in the following sections.

2.3.1 Prevention

The easiest way to avoid parthenium weed is to prevent it from establishing in the first

place (PAG, 2000). Simple precautions, such as sowing of uncontaminated crop and

pasture seeds, cleaning of cultivating and harvesting vehicles before moving them into non-

infested areas, and short term quarantine of stock that have been in parthenium weed

infested areas will reduce the spread of parthenium weed (Navie et al., 1996; PAG, 2000;

Parsons and Cuthbertson, 1992). Maintenance of grass crown cover in problem areas

(heavily grazed areas, watering points, roadsides, and holding paddocks, etc.) and spot

spraying of isolated outbreaks with a residual herbicide were recommended as they reduce

the occurrence and distribution of parthenium weed (PAG, 2000). Further this group

suggested that maintaining good hygiene on the field and property can also prevent the

spread of parthenium weed. Seed-check vehicles and controlling the movement of animals

can also help to control in the field.

2.3.2 Manual and Mechanical control

Manual and mechanical control methods are reported to be very expensive and cannot be

employed everywhere, and the relief from these methods is temporary and needs to be

repeated (Bhan et al., 1997). Mowing or slashing of parthenium weed is not recommended

for it results in rapid regeneration of plants from lateral shoots (Gupta and Sharma, 1977;

13

Haseler, 1976). However, deep ploughing greater than 7 cm soil depth to bury seeds or

repeated harrowing to destroy the seedlings before sowing is recommended (Bhan et al.,

1977; Tamado Tana, 2001). Bhan et al. (1997) also suggested that the plants should be

uprooted to prevent regeneration from the remaining lateral shoots and that such operation

should be done before flowering and when the soil is moist enough to facilitate easy

removal. The latter author also noted that hand pulling is recommended only in small areas

like in gardens, flower beds, intensively cultivated fields or high value crops since manual

removal is not cost effective. Mahadevappa (1997) and Bhan et al. (1997) recommended

that only persons insensitive to parthenium weed allergy shall be engaged; Gupta and

Sharma (1977) also suggested that protective clothing should be worn and subsequently

washed to prevent the possibility of allergic reaction.

2.3.3 Cultural control

Growing of competitive crops to suppress parthenium weed was also suggested as

alternative but, since parthenium weed grows in different ecology, the scope of this

practice is limited to only certain situation (Bhan et al., 1997). Kandasamy and Sankaran

(1997) conducted two field experiments at Tamil Nadu, India, to evaluate the competitive

ability of major field crops (cereals, millets, oilseeds, and pulses) and other plants

competitive with parthenium weed. They reported that growing of maize, sorghum and

sunflower significantly reduced the parthenium weed population by reducing its branching,

growth and flower head production as compared to other crops. In these crops, dry matter

accumulation of parthenium weed was reduced by more than 80% and the yield reduction

due to parthenium weed in maize, sorghum and sunflower was only 12.3, 14.7 and 14.1%,

respectively, indicating the competitive ability of this crops with parthenium weed.

2.3.4 Chemical control

Bromacil, diuron and terbacil, at 1.5 kg/ha (Kanchan and Jaychandra, 1977), diquat at 0.5

kg/ha (Dhanraj and Mitra, 1976) were reported to effectively control parthenium weed.

Spraying 2 kg/ha of 2, 4-D sodium salt or 2 l/ha of MCPA in 400 L. of water was found

14

effective to control parthenium weed at the seedling stage (Bhan et al., 1997). Balayan et

al. (1997) also reported 1-2% solution of glyphosate with or without surfactant and

Metribuzin at 1-2 kg/ha gave 90-98% visual toxicity on parthenium weed and advocated

the supremacy of chemical control over other control measures on the bases of quick relief,

time saving and cost effectiveness.

Chemical pollution of the environment, enormous cost, danger of toxicity to non-target

plants, necessity of the chemical application in non-agricultural areas, rapidity of re-

invasion of treated areas soon after the effect is diminished are the draw backs of chemical

control (Singh, 1997). Similarly, Bhan et al. (1997) reported that chemical control alone is

not justifiable as the effect of herbicide will always be of temporary nature and repeated

operations are required which will not remain cost effective. As parthenium weed is a weed

of wasteland and road side, a common man will never invest his money in this venture.

Moreover, plants suppressed by chemicals have been observed to regenerate after

remaining dormant for a few days. Chemical treatment can only kill existing population at

the given sites but cannot prevent the entry of the seeds from neighbouring places.

2.3.5 Biological control

Biotic factors suppress the plant within its native range as compared to its increased fitness

or vigour in their absence (Evans, 1997b). Hence, the fact of parthenium weed undoubted

vigour in Australia and India compared with its limited importance in the countries of

origin suggests that biotic factors contribute to its suppression there. If the natural enemies

were introduced, the ability of the plant to compete with pastures and crops could

conceivably be reduced to the point where it was no longer of economic importance

(Haseler, 1976). Therefore, biological control appeared to offer the best, long-term solution

for the management of parthenium weed and which is environmentally benign.

Biological control of parthenium weed was first proposed in India in 1970 and a brief

survey of insects attacking it was made in West Indies (Bennet and Cruttwell, 1971).

15

2.4 Geostatistics for spatial analysis

Geostatistics is concerned with “the study of phenomena that fluctuate in the space and/or

time”, (Olea, 1991). Geostatistics offers a way of describing the spatial continuity that is an

essential feature of many natural phenomena and provides adaptations of classical

regression techniques to take advantage of this continuity (Isaaks and Srivastava, 1989).

Moreover, geostatistics offers a collection of deterministic and statistical tools aimed at

understanding and modeling spatial variability (Deutsch and Journel, 1998). The main

application of geostatistics is the prediction of attribute values at unsampled locations

(Kriging) (ESRI, 2003).

The geostatistical spatial data modeling begins with the study of the variability of a sample

set, observed as points, that is considered representative of the attribute variation. A

theoretical semivariogram is fitted for the sample set and is used to determine weights for

the sample neighborhoods considered in the inference process (Webster and Oliver, 2001).

Therefore, the geostatistical inference procedures, the kriging and the stochastic simulation,

use the sample set and a correlation model to estimate attribute values in spatial locations

different from the samples locations (Isaaks and Srivastava, 1989).

The kriging procedure aims to estimate z values based on a weighted mean approach of the

z-sampled values of a local neighborhood. The kriging weights are determined from the

basic hypothesis of minimum variance of the error estimation and make use of the

theoretical semivariogram in order to calculate the covariance between two locations

(Isaaks and Srivastava, 1989; Webster and Oliver, 2001). The spatial distribution of P.

hysterophorus was determined by using the basic tools of geostatistics called variogram

(Webster and Oliver, 2001).

The variogram (γ) was calculated using equation 1 (Isaaks and Srivastava, 1989):

h (γ) = 0.5 E [{Zi(x)-Zi(x+h)}]2……………………………….1

Where x and x+h are two sample points, separated by distance h. E [.] is the mathematical

expectation and Zi(x) is the density of the P. hysterophorus at sample point location x.

16

The theoretical variogram which was used to measure the strength of statistical correlation

of the P. hysterophorus density as a function of distance h (Webster and Oliver, 2001) is

presented in fig 1.

Fig. 1 Theoretical features of a variogram (where (Si, Si) is location coordinate of location

i (ESRI, 2004).

3 MATERIALS AND METHODS

3.1 Description of the study area

3.1.1 Location

The study was conducted in Adami Tulu-Jido Kombolcha Woreda, which is part of the

East Showa Zone of the Oromia Regional State. Geographically the area is located between

38°20’ and 38.5°5’ and 7°35’and 8°05’. The Woreda covers an area of 1403.3 km2, and is

bordered by Southern Nations, Nationalities and Peoples’ Regional State (SNNPRS) in the

west and North West, Dugda-Bora Woreda in the north, Arsi Zone in the east and Arsi-

Negele Woreda in the south (Fig.2). Ziway (Battu) town is the administrative center of the

Woreda.

Ecologically, Adami Tulu-Jido is found in what is known as the Central Rift Valley of

Ethiopia in the southern part of Addis Ababa. Significant parts of the main rift valley lakes

of Ziway, Abijata and Langano are also found in the Woreda. The Woreda’s land mass lies

17

between 1500 & 2300 m a.s.l. except area around Mount Aluto. Major rivers in the Woreda

include: Bulbula, Jido, Hora Kalio and Gogessa. The Woreda is within sub-tropical agro-

climatic Zone (OSG, 1999; RGO, 2003).

Fig.2. Map of Adami Tulu-Jido Kombolcha Woreda

3.1.2 Topography

The Woreda is found in the northern part of the Central Rift Valley. The relief of the area is

characterized by plain and flat stretched land, with some small mountains, hills and gorges

(Fig. 3 and 4) (RGO, 2003).

Fig. 3 Elevation map of the sampling points in the Adami Tulu-Jido Kombolcha Woreda

18

Fig.4 Slope map of Adami Tulu-Jido Kombolcha 3.1.3 Vegetation and wild life

The major natural vegetation of the Woreda belongs to woodland and savanna (Acacia-

wood land and Savannah and Cenchrus- grasslands). Species composing the vegetation

predominantly belong to the genera Acacia and Balanites. Major wildlife of the Woreda are

warthog, duiker, monkey, tortoise, ape, greater kudu, great white pelican, flamingo,

hippopotamus, ostrich, bush buck, duck, hyena, rabbit, and kerkero. A small part of the

Shalla-Abijata National Park is in the Woreda (OSG, 1999; RGO, 2003).

Fig.5 The stand of parthenium weed (a) at road side of Ziway (b) at Edo Gojola area

19

3.1.4 Geology and Soil

The parent material consists of volcanic rocks of basalt and tuffs with rare rhyolites and

soils are whitish with coarse texture and freely draining. About 60.4%, 30.4% and 9.2% of

the Woreda were covered by Andosols, Rendzinas and phaeozems, and Luvisol soils

respectively (RGO, 2003). However, Vitric Andosols and Mollic Andosols dominate the

Woreda. Provided that there is adequate moisture, most of these soils are among the most

productive soils in the world. Other soils that are found in the Woreda include luvic

phalozems and lithosols. Andosols soils originate from volcano-lucustine deposits with

volcanic ashes, ciders, pumic (graves) lapilli. Fluvisols are derived from allvuium on the

lakes shores and along the Meki River. Gleyic-Mollic flvuisols are derived from lacustrine

deposited along the shore of Lake Ziway. They are deep, black, fine loamy and partly sodic

(RGO, 2003).

3.1.5 Climate

The Woreda has semi-arid and arid agro-climatic Zones. It receives an average annual

precipitation of 759.7 mm (RGO, 2003). The annual rainfall varies from a low of 513.92

mm in 1979 to a high of 1096.1 mm in 1976. About 41.49% of the annual rainfall is

recorded during the period from June to September. The driest months are November and

December; only 0.58% of the annual rainfall is recorded during this period. The mean

annual temperature is 19.98°C at Ziway station while it is 20.04°C at Adami-Tulu station.

The mean monthly temperature varies from 18.5°C to 21.6°C. May is the hottest month

with mean maximum temperature of 28°C. the coolest month is December with minimum

temperature of 10.7°C. The average air relative humidity is 72.75%, varying from 68%

(November) to 78% (July and September) on the monthly average (RGO, 2003).

20

Mean maximum and minimum temperature (0C) and Rain fall (mm) at Ziway station

020406080

100120140160

Jan

Feb

Mar

Apr

May

June

July

Aug

Sep

t

Oct

Nov

Dec

Months

tem

pera

ture

and

RF

Mean maxMean minRF

Mean maximum and minimum temperature (0C) and Rain fall(mm) at Adami Tulu station

020406080

100120140

Jan

Feb

Mar

Apr

May

June

July

Aug

Sep

t

Oct

Nov

Dec

Months

Tem

pera

ture

and

RF

Mean maxMean minRF

Fig. 6 Average means temperatures and rain fall at Ziway and Adami-Tulu stations

3.1.6 Population

The total population of Adami Tulu-Jido was 111,926 (28.5% urban) in 1994 (CSA, 1994).

The economically active (15-64) were 50% of the total population. Children below 15

years were 48%, while the elderly (65 years and above) were only 2%. Females were

49.3% of the urban and 50.3% of the rural population. The average household size in the

Woreda was 4.6, with 4.9 and 4.2 for rural and urban respectively. The population density

was 86 persons per km2 in the mentioned year (OSG, 1999).

3.2 Methodologies

3.2.1 Vegetation Survey

Sampling design

The samples of biophysical data were collected by using systematic grid sampling

techniques. In systematic grid sampling, samples are taken at regularly spaced intervals. An

initial location or time is chosen at random, and the remaining sampling locations are

defined so that all locations are at regular intervals over an area (grid) (Cressie, 1993).

Systematic grid sampling is used for mapping the spatial patterns or trends over time of P.

hysterophorus. At each grid points a 1 m by 1 m area was selected for collecting

biophysical data.

21

The combination of non-probability (purposive sampling) and random sampling techniques

were employed. The study area is selected using purposive sampling techniques. Major

PAs in Adami-Tulu-Jido Komblcha Woreda, where more dominated by P. hysterophorus

selected. Furthermore, among the Adami-Tulu-Jido Komblcha,“ Wolin Bulla”, “Rasa

Migira”, “Negalign”, “Abosa”, “Elka Jalamo”, “Edo Gojola”, Abina Germamo”,“Worjo

Weshgula”,”Widana Garbi Boramo” and “Adami Tulu” Kebeles/PAs were selected using

purposive sampling techniques.

A random sampling technique was used to determine the number of households who

participated in the assessment of socioeconomic and ecological impacts of the parthenium

weed. Moreover, the sample size was determined according to Bartlett et al. (2001).

3.2.2 Sampling of biophysical data

Data for the study was collected by combining physical survey with socio-economic

survey. Present day distribution of P. hysterophorus was assessed using systematic regular

grid sampling technique. This involved overlying regular grids of 2 km (L) x 2 km (W)

over the map of the study area, and collecting density per unit area of P. hysterophorus at

the intersection of each grid. At each grid spot, additional data on physical attributes such

as crop type often cultivated, slope, aspect, soil texture, soil fertility, and special

biophysical attributes that farmers suggest were collected. At the same spot, density of the

species nine years back was obtained by interviewing nine elderly farmers selected based

on cluster sampling technique. The clusters (in which the population is divided into

mutually exclusive groups and draws sample of the groups to interview randomly) are three

villages closest to the grid corner, and three elderly farmers were selected from each village

and interviewed. The average density estimate provided by the nine interviewed farmers

for the spot were recorded as density for the period nine years before present. The grid

intersections were navigated using GPS, and at each spot the coordinates and altitudes were

registered from the GPS reading.

22

The data collected mainly include ground truth data identified with transect walk and the

coordinates are recorded with GPS, the current density of the P. hysterophorus was

recorded by counting each plant head per square meter (m2 ) in every plot. The past density

also collected by interviewing nine elderly farmers from nearby three villages (three elders

from each village) and taking their averages for the past nine years back data in the same

area. Moreover, the density and the frequency of all the wild species in the selected area

were collected by counting in each 50 by 50 cm quadrats. Assessment was conducted in

different habitats (sectors): cultivated lands, vacant and/or waste lands, roadsides,

lakeshores and in grazing lands and woodlands to draw exhaustive inventory of parthenium

weed infestation.

3.2.3 Sampling of weed species

The impacts of parthenium weed on biodiversity were assessed, using the importance value

index to describe its importance. The importance Value index is useful to compare the

ecological significance of a particular species (Lamprecht, 1989; cited in Girma Balcha et

al., 2004). During the survey, all wild species growing along different wastelands,

roadsides and wetlands as well as grazing lands were collected and identified by referring

to Flora of Ethiopia and Eritrea in the National Herbarium of Ethiopia, Addis Ababa

University. The weed study was made following the list count method suggested by Raju

and Reddy (1998) and Shabbir and Bajwa (2006). The weeds were collected by counting

stem of each species per 50 cm by 50 cm quadrats. The importance value (IV) is the sum of

the relative density (RD) and relative frequency (RF) of species in a stand. The sampling

was conducted randomly in all selected plots of Adami Tulu-Jido Kombolcha Woreda.

Finally the compiled data were analyzed for biodiversity studies using the following

equations:

100(%) ∗=eciescyforallsputefrequenTotalabsol

eseniumspeicueforParthequencyvalAbsolutefrRF ………..2

100(%) ∗=esorallspeciutedensitfTotalabsol

venspeciesnsityforgiAbsolutedeRD ………………...3 RFRDIV +=(%) …………………………………...4

23

3.2.4 Socioeconomic Survey

The study site i.e. Kebeles or Peasant Associations (PAs) were selected based on purposive

sampling technique for socioeconomic study. Representative Kebeles/PAs in the Woreda

were selected, then representative villages within association, and farmers within villages.

Fields were selected regardless of size, and on the grounds of accessibility (adjacent to

road) and whether it carried the required amount of P. hysterophorus i.e. its degree of

infestation. These Kebeles were selected because; they are good prospects for accurate

information and also are highly infested by P. hysterophorus in the Woreda. The number

of samples was determined based on Bartlett et al. (2001), techniques. Additionally, using

semi-structured questionnaires data were collected to make analysis on the socio-economic

and environmental impacts of P. hysterophorus. The total number of respondents was 160

at α= 0.05 level. This is more reliable and representative to give accurate analysis inference

on the socio-economic and ecological impacts of the parthenium weed in the Woreda.

3.2.5 Environmental factors data

Finally, data on major environmental factors and crop management practices believed to

influence P. hysterophorus distribution in each field were collected by observation and feel

methods with the help of DAs and farmers (soil texture and fertility, topography, type of

crop and current land use type), measurement (altitude, slope, aspect), interviewing farmers

(number of ploughings before planting, fertilizer use, and crop pattern) or from secondary

sources (administrative Kebeles, rainfall, temperature, humidity). Environmental and crop

management variables of nominal type (Soil texture, soil fertility, crop type, current land

use, fertilizer use) were converted into binary dummy variables that take the value 1 if the

field belongs to the category or 0 if it does not. Altitude, number of ploughings, density of

both past and present (per m2) and slope in % were quantitative variables and hence

measured on an interval scale.

24

3.2.6 Data analysis

The biophysical data obtained from the field were analyzed using Ms-Excel, Geostatistics

and ArcGIS 9.1 software. The data from Ms-Excel imported into ArcGIS. In ArcGIS,

spatial analyst and Geostatistical analyst components were used to synthesis maps of past

and present distribution of P. hysterophorus, elevation and slope. Similarly, maps of some

of the quantitative parameters such as slope and altitudes were mapped to investigate the

association between the distribution of the weed and physical parameters. Similarly,

correlation and regression analyses were performed for the weed density and other physical

parameters such as slope to investigate which factors favor the species and to evaluate the

fitness of the model. The socioeconomic and other biophysical data are analyzed by using

SPSS Version 13.0 software. The plot data (slope, altitude, soil texture and fertility, farm

management, current land use, crop type, and other biophysical data), the results were used

to determine the correlation between the rate of distribution and density of the parthenium

weed in the study area. It was also used to determine the potential distribution of

parthenium weed in the Woreda.

Experimental variogram

In this research the experimental variogram which is the variogram computed from the

sample data (Webester and Oliver, 2001) was assessed at different lag sizes (cut-off) before

fitting the model. The appropriate lag spacing for the experimental variogram was

determined by generating and visually inspecting several experimental variograms. The

variogram were calculated with different lag spacing by observing which variogram best

revealed the spatially dependent correlation of the data (Isaaks and Srivastava, 1989) and

also with visual observation (Webester and Oliver, 2001). The model fitting was done for

the empirical variogram values.

Spherical model (equation) was used for predicting P. hysterophorus weed density in this

research. This model rises from the nugget value almost linearly and reaches an absolute

25

sill value at distance of range (Webster and Oliver, 2001). The spherical model is described

to be the best model for vegetation parameters prediction (Wallace et al., 2000).

Spherical model:

γs(h) = Cο+C1 [(23 (

ah )-

21 (

ah ))3] for h<=a ……………………..5

And γs(h) = Cο+C1, for h >a

Where Co = nugget, C1= sill, h= distance, a= range (Isaaks and Srivastava, 1989)

Figure 7 Summary of flow chart that shows general methodology of the study

Data for 2007

Data for 1999

Socio-economic

d t

Delineating study area

Collecting secondary data

Delineating study area

Data collection, display and

interpolation

Map 2000

Distribution change analysis –correlation with biophysical

attributes

Analyzing Socio-

economic data

Map 2007

Parthenium weed distribution Map

Data collection, display and interpolation

26

Kriging

The aim of kriging is to estimate the value of a random variable at one or more unsampled

points or over larger blocks, from more or less sparse sample data on a given support

(Webester and Oliver, 2001).

Two kriging methods were selected and assessed for P. hysterophorus weed distribution

prediction. These methods include: Simple Kriging (SK) and Ordinary Kriging (OK).

These kriging methods were tested for their best performance, OK was found the best

method and the actual prediction mapping of parthenium weed was done using this method.

In the actual map production using kriging, four major steps were taken in this research.

These steps were determination of the variogram, fitting a model to the variogram

prediction of the values at the nodes of a fine meshed grid and finally presentation of the

results (Chiles and Delfiner, 1999; ILWS, 2001; Isaaks and Srivastava, 1989; Webester and

Oliver, 2001). A general overview of the methods employed in the assessment of

parthenium weed is presented in Fig. 7.

Table 1 Kriging parameters for P. hysterophorus computed using variogram analysis.

Type of environmental factors

Model type Nugget Effect

Sill

Elevation Spherical 0 513.48 Current density Spherical 765.16 298.86 Past density Spherical 72.864 0 Slope Spherical 3.966 2.4204 Current land use type

Spherical 1.083 0.26263

If a variogram displays a leveling-off behavior, then the variogram value at which the

plotted points level off is known as the "sill" (Fig. 1). The value of the sill is usually

equivalent to the traditional sample variance. The distance at which the variogram values

level off is known as the "range." The range designates the average distance within which

27

the samples remain correlated spatially. Variograms that do not demonstrate a leveling off

imply that the range is beyond the maximum appropriate distance represented.

The variogram value at which the model appears to intercept the ordinate is known as the

"nugget." The spatial characteristics of these nuggets impart unexplained variability in the

modeling of the variable (Webester and Oliver, 2001). A nugget represents two, often co-

occurring, sources of variability. One source derives from spatial variability at a scale

smaller than the minimum lag distance, and hence it cannot be modeled with the present

sampling scheme. The other genesis of a nugget is experimental error which is sometimes

referred to as the "human nugget." Interpretations made from variograms depend on the

size of the nugget because the difference between the nugget and the sill (if there is one)

represents the proportion of the total sample variance that can be modeled as spatial

variability (Webester and Oliver, 2001).

4 RESULTS AND DISCUSSION 4.1 Distribution of parthenium weeds in the Woreda

4.1.1 Past distribution of P. hysterophorus

Farmers in the study area believe that P. hysterophorus was introduced into the area

following road construction project of the highway from Modjo to Awassa in 1999/2000.

Indeed, the invasion of P. hysterophorus in the Woreda began before nine years. Since then

it expanded at alarming rate in all directions mainly following slope gradient (Fig. 8).

In areas where parthenium infested highly its rate of infestation is strong enough to cover

large areas (Fig. 8). The analysis also showed that, past and current density (per m2) of the

parthenium weed is positively related (r = 0.822). Furthermore, the relation between past

and current density is significant at p < 0.01 (0.00).

28

Association between current and past density (per square meter) with slope (%)

0

50

100

150

200

1-3(%) 3-6(%) 6-9(%) 9-12(%)

slope

dens

ity

currentpastPower (current)

Fig.8 Association between parthenium weed density with slope

As figure nine below depicts the density of P. hysterophorus in the past was highly

concentrated at Negalign and part of Elka Jelemo following the main road from Modjo to

Awassa. P. hysterophorus was highly concentrated around north-eastern part of the

Woreda, close to Lake Ziway with maximum value of 61 plants per m2. The next highest

density range occurred at Abosa, Wollin Bulla, Ziway, part of Edo Gojola, Elka Jelemo,

and Abina Garmamo Kebeles in the Woreda. Generally past density distribution of

parthenium weed occurred following the main road in the north-east parts from Abosa

town down to Ziway city.

29

Fig 9 Parthenium weed distribution nine years ago in the study area

Even though, there are different factors that favor fast distribution of the weed, flooding

and movement of vehicles are the major factors. This radiation occurs particularly in the

direction of low slope and waterways. Fig. 8 also depicted that the correlation between

slope and distribution of the weed in the different Kebeles within the Woreda. From the

figure it can be seen that there is no strong association between density of infestation and

ground slope. This is also true statistically as there is weak and negative, correlation

between parthenium weed density and slope in the study area (r = -0.052). This could be

due to the generally flat topography of the area. Although slope does not appear a limiting

factor for dissemination of P. hysterophorus in the Woreda, however, parthenium weed

was also observed in areas of relatively higher altitudes of the Woreda particularly at Rasa

Migira. This is against the normal route of flooding. But according to key informants and

farmers this is happening due to construction activities and vehicles and other human

activities.

30

4.1.2 Current distribution of P. hysterophorus

Though parthenium weed in the Woreda was introduced recently, it is covering large area

in the Woreda as shown in Fig. 10. The figure reveals that the infestation is radiating from

a localized source, which confirms the perception of the locals. The localized infestation of

parthenium weed was observed on roadsides, and the highest densities that overlap with the

map were also recorded in the field from the north eastern parts of the Woreda, close to

Lake Ziway. The highest density (plants per m2) was 319 at around Edo Gojola.

Furthermore, the high infested northeastern part of the Woreda is also the area that had the

highest infestation of P. hysterophorus in the past (Fig. 9). In particular, following both

sides of the main road, at Abosa, Negalign, Elka Jelemo, Abina Garmamo, and Ziway city

showed a high infestation. These Kebeles are those adjacent to Lake Ziway and may have

relatively better moisture contents in the Woreda.

Generally the weed is found in areas of low altitude and flatter topography and near to

areas towards Lake Ziway (Fig 10). As also shown by the overlap of highest density spots

from Figs. 8 and 10, there is a correlation (r = 0.822) between past as well as current

distribution of P. hysterophorus and it is significant at p < 0.05. In areas of high

P. hysterophorus density in the past there was also a high relative density per m2 currently

as depicted in Fig. 10. This is probably due to high viability of the parthenium weed seed

banks in soil (Tamado Tana, 2001). Thus parthenium weed density per m2 is often

increasing in every generation, unless intervention is taken to control its spread. Bhan et al.

(1997) also suggested the same patterns.

31

Fig.10 Map of P. hysterophorus current density distribution in Adami Tulu-Jido

Kombolcha

4.1.3 Environmental factors that favor or disfavor the distribution of the species

Soil texture and both past and current parthenium weed density per m2 are positively

correlated r = 0.209 and r=0.258, respectively. This correlation is significant at p= 0.05

(0.01 and 0.001 respectively), and also there is negative co-relation between soil fertility

and past and current density (-0.222 and -0.267 respectively). Thus there is a correlation

between the past and current density of P. hysterophorus and texture of soil but its fertility

in the study area is negatively correlated and do not influence parthenium weed distribution

in the study area. In other words soil texture will favor the fast distribution of P.

hysterophorus, while its fertility does not affect despite the fact that parthenium weed can

grow in any type of soil environment. There is also weak but positive correlation between

past and current density and number of plough per season r = 0.052 and r= 0.111

respectively (Table 2).

32

33

Parthenium hysterophorus density (past and current) and fertilizer application are also

positively but weakly correlated (r = 0.271) and (r = 0.366) respectively. These correlations

are significant at p= 0.01 (0.001) and p= 0.05(0.000) respectively. The Kebeles with high

infestation of P. hysterophorus used fertilizer. There is positive but weak correlation

between current land use and both past and current density of parthenium weed in the

Woreda r = 0.126 and r = 0.127 respectively (Table 2). On the contrary, the distribution of P. hysterophorus did not show strong variation with

altitude, slope and aspect in the study area. The correlation between altitude and both past

and current density of the parthenium weed is negative and weak (r = -0.053 and r= -0.025

respectively). This implies that there is no strong correlation between altitude and

parthenium weed density. This may be due to the absence of significant difference in

elevation in the Woreda (Fig.2). Moreover, there is also no significant correlation between

aspect and parthenium weed distribution. Thus rate of parthenium weed distribution is not

influenced by both elevation and aspect in the study area. This observation differ from the

study by Tamado Tana (2001), who showed that altitude, rainfall, month of planting,

number of weedings and soil type were the major environmental/crop management factors

influencing the species distribution in the study area. In the present study, however, soil

texture, land use type, crop type, number of plough before sawing, and application of

fertilizer favor the fast distribution of parthenium weed, while elevation, slope, soil fertility

and aspect do not favor its fast dissemination into different Kebeles.

34

Table 2 Results of correlations of some of biophysical data

Parameters Altitude(m)

Current density(per m2)

Past density (per m2)

Slope (%)

Soil texture

Soil fertility Aspect

Current land use

No of plough

Fertilizer use

Altitude

Pearson Correlation

1 -0.025 -0.053 0.181* 0.097 -.187* -0.063 -0.164* -0.060 -0.003

Sig.(2-tailed) 0.762 0.518 0.026 0.237 0.022 0.446 0.044 0.462 0.971

Current density

Pearson Correlation

-0.025 1 0.822** -0.004 0.258** -0.267** -0.104 0.126 0.111 0.366**

Sig.(2-tailed) 0.762 .000 0.958 0.001 0.001 0.207 0.123 0.176 0.000

Past density

Pearson Correlation

-0.053 0.822** 1 -0.025 0.209* -0.222** 0.004 0.127 0.052 0.271**

Sig.(2-tailed) 0.518 0.000 0.758 0.010 0.006 0.960 0.122 0.525 0.001

N*** 150 150 150 150 150 150 150 150 150 150 * Correlation is significant at the 0.05 level (2-tailed). ** Correlation is significant at the 0.01 level (2-tailed). *** N is total number of grid points

4.1.4 Infestation of P. hysterophorus

Parthenium weed was observed in the Woreda to grow on roadsides, wastelands, in towns,

villages, gardens, waterways, grasslands, wetlands and in crop fields both during cropping

season and after harvest. However, regarding the time when the weed is introduced to the

Woreda, farmers varied considerably on their perception. Few indicated that the weed was

observed in the Woreda nearly nine years ago while the majority of the farmers have the

perception that it was introduced to the Woreda recently (Fig. 11).

2007200620052004200320022001200019991998

Year of Infestation

Fig. 11 Year of infestation of Parthenium hysterophorus (in %) as perceived by farmers in

the study area of the Adami Tulu-Jido Kombolcha Woreda

The intensity of parthenium weed infestation of crop fields in the Woreda varied from field

to field depending on the time of the weed’s introduction into the area and the efforts made

by the farmers to control it. It recently became a major crop weed across Wolin Bulla, Rasa

Migira, Elka Jalamo, Negalign, and Edo Gojola Kebeles of Adami Tulu-Jido Kombolcha

Woreda (Table 3 and Figs. 9 and 10). Severe infestation, which corresponds to more than

20 plants per m2 density or scale of 5 (Table 3), was observed in sorghum, maize and wheat

fields around Rasa Migira, Elka Jalamo, Negalign, and Edo Gojola and in sorghum, maize

and tef fields around Rasa Migira both during the growing period (May-September, 2007)

35

and after harvesting time. The scale of importance of the parthenium weed for these areas

was also 4 except Edo Gojola (3) showing very serious or heavy yield reduction due to the

weed.

Similarly, in Wolin Bulla, Adami Tulu, Worjo Weshgula, Widana Garbi Boramo and Edo

Gojola heavy infestation of parthenium weed in the sorghum and maize field as well as

irrigated land was observed both during fallow and cropping seasons. In Adami Tulu,

parthenium weed had entered crop fields having a scale of infestation 3 and importance of

2 (Table 3).

Table 3 Distribution and scale of parthenium weed infestation in Adami Tulu-Jido Kombolcha Location

Altitude (m)

Texture class

Infested habitat*

Scale of infestation (0 – 5)**

Importance (1 – 4) ***

Wolin Bulla 1673 Sandy loam 5 5 3 Negalign 1691 Sandy loam 5 5 4 Rasa Migira 1763 Sandy clay 5 5 4 Elka Jalamo 1660 Sandy loam 4 5 4 Edo Gojola 1657 Sandy 5 5 3 Ziway 1647 Sandy 3 5 3 Widna Garbi Boramo

1667 Sandy 1,2,3 2 1

Adami Tulu 1660 Sandy clay 3 3 2 Abina Garmamo 1654 Sandy 1,2,3 5 3 Worjo Weshgula 1670 Sandy clay 4 1 2 Kemo Gerbi 1648 Sandy clay 1,3,4 5 3 Anano Toro 1668 Sandy 4 3 2 Widna Gerbi 1676 Sandy clay 4 3 2 Tulcha 1662 Sandy 1 2 1 Abosa 1662 Sandy loam 1 2 3 *Infested habitats: 1 = road sides; 2 = range lands; 3 = gardens and villages; 4 = crop

fields; 5= all habitats;

36

**Scale of infestation: 0= no parthenium weed in the field, 1= beginning or presence of

parthenium weed only on road sides, 2= presence of parthenium weed infestation on road

sides and

non- crop lands, 3= infestation on road sides, non-agricultural lands and beginning on crop

lands, 4= infestation on crop fields up to 20 plants per m2 and 5= severe infestation of

parthenium weed (> 20 plants per m2).

*** Importance of parthenium weed in the area: 1 = no parthenium weed in the crop field;

2 = not serious (present at low density); 3 = serious (moderate yield loss); 4 = very serious

(heavy yield loss).

Wide range distribution of the weed in the Woreda as well as observation of its growth in

all forms of ecosystem conforms to previous study reports. For instance, Taye Tessema

(2002) reported parthenium weed to grow in different agro-ecological Zones, from hot arid

and semi arid low altitude to humid high mid altitude (920 at Awash and 2350 at Chelenko)

m a.s.l. as well as on any type of soil (sand, loam or clay) and in different habitat

(roadsides, wastelands, rangelands, villages, towns, gardens, crop fields and shore sides).

Hedberg et al. (2004) also reported that parthenium weed can grow at altitude of 900-1800

m a.s.l. This indicates that the species has wider ecological amplitude and adaptability. According to the farmers in the Woreda, grazing land and roadside are the two highly

infested habitats (Table 4), while about 49.1% of the farmers also indicated that the weed

first appeared on road side.

37

Table 4 Farmers view of the first appearance of the weed in the Woreda of the study area

Habitat Frequency Percent (%) Grazing land 8 5 Irrigated land 10 6.2 Road side 79 49.1 Waste land 30 18.6 Grazing and irrigated land 1 0.6 Grazing and road

5 3.1 Irrigated and road side 9 5.6 Irrigated and Waste

2 1.2 Road side and Waste

15 9.3

Farmers’ view of the infestation habitat conforms with field observation. It was noted that,

parthenium weed population is high in places where the soils are disturbed constantly for

purposes of construction of road, buildings, and waterways for irrigation channels.

Therefore, the extensive density along roadsides in different Kebeles might be due to the

routine disturbance and grading of road verges and transportation of sands and gravels

from parthenium weed infested to non-infested areas. This observation is in line with

Shabbir and Bajwa (2006), GISP (2004) and Huy and Seghal (2004). This might have

helped the dispersal of the weed thereby contributing to severe infestation and invasion of

parthenium weed in the Woreda particularly in the Rasa Migira (Fig. 10).

According to interviewed farmers and DAs, the weed was spread into the Woreda through

vehicles during road construction from Modjo to Awassa through different means since

1999/2000. In addition, construction materials had played a significant role for fast rate of

dissemination/distribution of the weed.

Many mechanisms were suspected by farmers as a means for its fast distribution in the

Woreda (Table 4). According to farmers, these dissemination mechanisms include: wind

6.3%, flood 46.3%, and vehicles 51.2% and other mechanism 41.3%. Among these major

38

dispersal mechanisms flooding and vehicle 46.3% and 51.3% respectively, took the lead

for its fast rate of distribution in to different Kebeles within the Woreda.

Table 5 Farmers view on the agents for the fast spread of parthenium weed in the Woreda

Means of introduction Frequency Percent (%)

Through fodder 2 1.3 Human activity

5 3.1

Animal movement 5 3.1 Vehicle 82 51.2 Seed 8 5 Wind 10 6.3 Flood 74 46.3 Other mechanism 66 41.3

Farmers also included livestock as a mechanism for the weed distribution. This is because

of unrestricted movement of animals to Lake Ziway for watering. These mechanisms

identified by farmers agree with studies of other scholars such as Auld et al. (1983), who

stated that local dispersal of P. hysterophorus seeds occur locally by wind and water, while

motor vehicles, machinery and livestock movements, crop and pasture seeds contribute for

long distance dispersal.

In areas weeding is not done as frequently and systematically, it is very common to see

dense stands of parthenium weed as pure stands. It is also observed that the weed grows in

the fallow period in fields where only one or few crop is grown in a year. According to the

farmers and field observation, parthenium weed has been observed in the field germinating

and growing even during dry periods with one or two showers. This might be due to its

relative low moisture requirement for germination and its drought resistance capacity

thereby suppressing other plant species (Taye Tessema, 2002.)

4.1.5 Farmers’ practices to control P. hysterophorus

Like other weeds, control of parthenium weed in the Woreda is entirely based on cultural

and labour intensive practices such as tillage, hand weeding, mowing, hoeing and slashing.

39

These control methods are currently practiced by more than 90% of farmers (Table 6).

Unlike large-scale farms in developed and developing countries, small-scale farmers

prepare their land using repeated oxen ploughing and/or hoeing. Almost all (> 99.9%) of

the farmers in the Woreda use oxen and/or hand hoeing for ploughing their plots and about

41.9% of the farmers ploughed three times before sawing (Appendix 6). This traditional

method of ploughing practice was not an efficient method to control parthenium weed

distribution; rather it increases from time to time since its invasions. Because of extended

root system deep into the soil, mature plants of parthenium weed are difficult to remove

completely (Bhan et al., 1997). Most of the farmers in the study area began to take measure

since 2005, while quite large numbers do not take any measure at all (Table 7). Still few

farmers were observed to mow parthenium weed infested fields at first and then plough

using ox-plough. Still, uprooting is

difficult unless ploughing is done at the time when there is enough moisture in the soil to

ease uprooting of parthenium weed. Further, most farmers suggested that, the fields with

high infestation of P. hysterophorus are difficult to mow and plough.

Table 6 Farmers’ response on the type of measures to control dissemination of parthenium

weed in the study area

Methods of control of parthenium weed

Frequency Percent (%)

Weeding and burning 147 91.9

Fallowing 1 0.6 chemicals 5 3.1

40

Table 7 The period in which P. hysterophorus was observed and farmers started taking

control measures in different Kebeles in the Woreda

Period of control action taken by farmers Frequency Percent (%)

2000 1 0.6 2002 2 1.2 2003 2 1.2 2004 9 5.6 2005 57 35.4 2006 39 24.2 2007 6 3.7 Total 160 99.4

In the Rasa Migira, Elka Jalamo, Negalign, and Edo Gojola parts of the Woreda, intensive

hand weeding and/or hoeing and burning were practiced in crop fields like maize and

sorghum to control further dissemination (Table 6). But farmers, who practiced hand

weeding and/or hoeing (91.9%), suggested that the parthenium weed multiplies in the next

crop season hence, this method is not a permanent solution to control further spread. This

agrees with the report of Bhan et al. (1997) who suggested that manual and mechanical

control methods give temporary solutions because P. hysterophorus covers large areas.

These authors also stated that no single method of control of P. hysterophorus has proved

satisfactory as each method suffers from one or more limitations. Mowing or slashing of

P. hysterophorus is not recommended since this would result in rapid regeneration of plants

from lateral shoots (Gupta and Sharma, 1977). It is suggested that P. hysterophorus should

be uprooted to prevent regeneration from the remaining lateral shoots and that such

operation should be done before flowering and when the soil is moist enough to facilitate

easy removal.

However, by weeding and/or hoeing and burning, farmers tried to keep the level of

infestation of their crop fields low though some farmers reported to suffer from parthenium

weed associated health problems such as allergy and dermatitis (18.8%, n=160) including

in some cases headaches and fever (Appendix 5). To avoid the problems, farmers wear

plastic bags while hand weeding. However, farmers do not want to weed parthenium weed

from communal lands, such as field borders, wastelands, water ways and road sides. Hence,

41

it grows and sets seeds in these areas from where it re-infests and spreads itself to other

areas. In some cases, farmers are advised by experts from the agriculture office of the

Woreda to eradicate by mowing and/or slashing parthenium weed growing in their village,

garden, fields, roadsides, and grass lands through campaigns.

4.2 Socio-Economic and Environmental Impacts of P. hysterophorus

Of the interviewed farmers, 86.3% in the Woreda were aware of the problem the weed

causes on crop and/or grazing land. Some of these respondents consider P. hysterophorus

to be the most important weed both in the grazing land and crop field. However, in the

Wollin Bulla almost all farmers consider it as a roadside weed only (65%, N=20). These

figures show that the problem caused by the weed is not currently felt equally by all

farmers across the Woreda. However, as reported by Haseler (1976) the initial occurrence

of P. hysterophorus in a new area usually occurs along roadsides and it is from this

foothold that it spreads extensively into agricultural land, as observed in Wollin Bulla

(personal observation). Moreover, the interviewed farmers and other professionals reported

that there is no benefit attached to the weed thus far.

The farmers interviewed indicated that P. hysterophorus has a number of socio-economic

impacts that include effect on crop and livestock production, human health and biodiversity

(Table 8). These findings are in line with the studies by Kohli & Rani (1992) and Evans

(1997a) who reported a number of environmental and agricultural problems, such as the

loss of crop productivity, fodder scarcity, biodiversity depletion and health problems for

human beings and livestock. Therefore, P. hysterophorus contributes to social instability

and economic hardship, placing constraints on sustainable development, economic

development, poverty alleviation and food security.

42

Table 8 Types of damages caused by parthenium weed as ranked by farmers

Types of damage Number of respondents (%)

Remark

Crop production 44 Reduction of yield quality and quantity

Livestock 30.6 Health and productivity

Health impacts 18.8 Human health

Impacts on biodiversity

100 It has no environmental benefits

4.2.1 Effects on biodiversity

The survey made in Adami Tulu-Jido Woreda revealed a total of 21 weed species that were

associated with P. hysterophorus (Table 9 and appendices 2 and 3). The most important

families, based on the number of family, were Compositeae (6) followed by Gramineae (4),

and it is noteworthy that two of the weeds ranked by farmers as most troublesome (Table

10) were quite recently introduced P. hysterophorus L. and Argemone mexicana L.

Furthermore, A. mexicana L. was also reported by the farmers to be recent introduction to

their areas. Hence, there is reason to be aware of the danger of introduction of new species.

Almost all the selected areas of Kebeles in the Woreda had a heavy infestation of P.

hysterophorus except Wollin Bulla.

Table 9 List of weed species in Adami Tulu-Jido Kombolcha (field observation) Scientific name

Family name English name

Local name Origin Worst affected area

Galinsoga parvifolra

Compositae Gllant soldier

Aba Tabo Peru

Range land and crop field

Xanthium strumarium L. (X.abyssinicum)

Compositae Cocklebur Metene Central America

Crop field

Oxygonum sinuatum

Polygonaceae Double thorn

Rafu hare/Sogdo

*NF

Range land and crop field

43

Digitaria velutina

Gramineae NF

Shubbo(O) NF

Range land

Datura stramonium L.

Solanaceae Thorn apple Manji(banji) Abyssinia

Range land, and crop field

Bidens pilosa L. Compositae Black jack Chigogot Tropical America

Range land

Cyperus rotundus

Cyperaceae Purple nutsedge

Kundi NF

Road side and crop field

Cynodon dactylon L.

Gramineae Bermuda grass

Korto NF

All habitats

Snowdenia polystachya

Gramineae NF

Muja NF

Range land

Alternanthera pungens L. (= A. repens)

Amaranthaceae NF

Safela NF

Crop field and west land

Commelina latifolia

Commelinaceae Water maker

Laluncha NF

West land

Erucastrum pachypodium

Cruciterae NF

NF

N F

Rang land and crop field

Guizotia seabra Compositae NF NF NF Rang land Tribulus terrestris

Zygophyllaceae Puncture vine

NF

NF

Crop field

Xanthium spinosum L.

Compositae Spiny cocklebur

Yeset Milas Central and South America


Parthenium hysterophorus L.

Compositae Congress weed

Farmsisa Mexico and central America

Road side and range lands

Solanum indicum

Solanaceae NF

Inbawy West land

Lantana camera L.

Verbenaceae Lantana Yewofe kolo

USA Road side and west land

Setaria pumila (=S.pallide-fusca)

Gramineae NF

Yewisha sendedo

NF

West land

Cyperus regitidipholus

Cyperaceae NF

NF

NF


Argemonne mexicana

Papaveraceae Mexican poppy

NF

Central America

Road side and west land

*NF Not Found

44

The analysis of the data collected from grazing land of the study area revealed that

P. hysterophorus was accompanied by nine other weed species. Galinsoga parviflora (Aba

Tabo) was the most dominant plant species, with an importance value (IV) of 61.15%

(Table 10). This was followed by P. hysterophorus and Digitaria velutina (Shero) with IV

of 22.65% and 21.09% respectively.

This area was also inhabited by a high diversity of weeds; a total of ten species was found

in this sector followed by crop field, which has also nine plant species. However,

P. hysterophorus is becoming the most dominant weed species within a short time since its

introduction.

Parthenium hysterophorus with the highest IV (i.e101.5%), followed by Cynodon dactylon

L. (Korto) species with IV values of 25.84% were observed in road side. It is particularly

roadsides sector in which parthenium weed highly dominates and competes with other

native and non- native roadside plant species. Moreover, this sector also consists of the

least compositions of plant species even compared with the same sectors without

parthenium weed invasions. This is a clear indication for allelopathic potential of P.

hysterophorus. Similarly, Krishnamurthy et al. (1997) described the allelopathic nature of

P. hysterophorus and its impact on plant diversity. Allelopathic interference also has been

well-demonstrated in Parthenium weed and almost all the plant parts, including pollen and

trichomes, are allelopathic (Kohli & Rani, 1992; Evans, 1997a). Tadelle Tefera (2002) also

described that the impacts of aqueous extracts from Parthenium weed leaf, stem, flower and

root parts exhibited allelopathic activity on tef seed germination and seedling growth.

The crop field sector in another plot area were found to be least dominated by parthenium

weed and maximum management were practiced. The analysis of data collected from this

field of the study area, reveled that P. hysterophorus was accompanied by eight other plant

species. Oxygonum sinuatum (Rafu hare), C. dactylon and P. hysterophorus codominant

with IVs 30.78%, 24.99% and 23.05% respectively (Table 10). However, P. hysterophorus

had a frequent to occasional level of occurrence in this sector.

45

The analysis of data conducted on wet land (shore side) indicated that there were only two

species, P. hysterophorus and C. dactylon with IVs 31.43% and 101.22% respectively. This

sector was the least diversed and dominated by C. dactylon (Table 10). However, this

sector soon or later will invaded by P. hysterophorus if not any control action taken by

responsible agents.

Analysis of data collected from waste land showed that it was inhabited by six plant

species. P. hysterophorus and Lantana camara (yewofe kolo) were codominating the plots

with IVs of 62.53% and 50.52% respectively (Table 10). Plot six which was also belong to

crop field sectors, dominated by O. sinuatum and P. hysterophorus with IVs 37.7% and

29.2% respectively. However, in this plot parthenium weed is becoming dominant and

completely might dominate within a short time, because of its allelopathic potential.

Analysis of grazing land in another Kebele also exhibited a total of four weed species

associated with P. hysterophorus. P. hysterophorus was the most dominant weed species of

this sector, G. parvifolra, and Guizotia seabra (Hada Dima) as codominant. P.

hysterophorus had the highest IVs of 77.26% (Table 10).

Parthenium hysterophorus was also the most dominant weed species of crop field in

different Kebele with IVs of 74.52% (Table 10). The observation further revealed that most

of the field was vegetated with other weed species, such as G. parvifolra and Cyperus

rotundus. Road side in another sectors also highly dominated by P. hysterophorus with IVs

of 75.87% and followed by C.dactylon with IV of 55.12%.

The analysis of the data collected again from the roadside in the Woreda showed that P.

hysterophorus was extremely dominant and associated with only four weeds species.

Among them P. hysterophorus had the highest IV (95.41%). Being codominant with P.

hysterophorus, C. dactylon showed the second highest IV (33.61%) (Table 10). Analysis of

data collected from control site, showed that, C.dactylon dominates this sector with IV

(48.88%). This plot was not invaded by parthenium weed.

46

47

Parthenium hysterophorus has become a major weed of various habitats in different

Kebeles in the Woreda in a relatively short time. According to farmers of the study sites,

DAs and my personal observation, both water and air are suspected to be the major agents

of its spread in arable as well as non-arable parts of the Kebeles.

The high relative IV of P. hysterophorus may be attributed to its aggressiveness and

allelopathic effects on the neighboring plants (Kohli et al., 1985; Adkins& Sowerby, 1996).

Naviel et al. (1996) and TamadoTana (2001) emphasized several other aspects of the

ecology of this weed that appear to contribute to its aggressiveness, including the size and

persistence of its soil seed bank, the high viability of seeds when buried, a fast germination

rate, and the innate dormancy mechanism of its seeds. Joshi (1991) recorded that P.

hysterophorus is an extremely prolific seed producer, with up to 2,500 seeds per plant, and

that it has an enormous seed bank in abandoned fields. Once dominant, P. hysterophorus

continues to persist as a pure stand or weed monoculture until it is managed (Shabbir and

Bajwa, 2006). It was noticed during the survey that P. hysterophorus prefers to invade

areas that have been recently disturbed and where topsoil is removed. This, in turn,

minimizes the competition from native species and enhances the chances of survival of the

P. hysterophorus, invading plant. It is further demonstrated that this weed has aggressively

colonized the open land, pasture, wasteland, wetland, and crop land of Adami Tulu-Jido

Woreda. This was also reported by Shabbir and Bajwa (2006) in Islamabad.

48

Table 10. Importance value (IV) of species in different habitats in selected sectors/areas (source: survey result)

IV (%) Weeds of selected habitat

Range land

Road side

Waste land wet land

Waste land

Crop field

Range land

Crop field

Road side

Road side Control

Galinsoga parvifolra 61.2 __ 19.2 __ __ 10.9 26.9 __ __ __ Xanthium strumarium (X.abyssinicum)

__ __ __ __ __ ___ __ __ __ __ 4.86

Oxygonum sinuatum 9.42 __ 30.8 __ __ 37.7 __ __ __ 8.91 __Digitaria velutina 21.1 __ __ __ __ __ __ __ __ __ 21.5Datura stramonium L. 12.9 __ 15.4 __ __ 17.7 __ 9.83 __ __ __Bidens pilosa L. 12.3 __ __ __ __ __ __ __ __Cyperus rotundus __ 12.1 __ __ __ __ __ 26.9 __ 10.1 48.9Cynodon dactylon L. 15.2 25.8 25 101 __ __ 45.7 __ 55.1 33.6 22.3Snowdenia polystachya 3.64 __ __ __ __ __ __ __ __ __ __Alternanthera pungens L.(= A. repens)

__ __ 15.4 __ __ __ __ __ __ __ __

Commelina latitalia __ __ __ __ 7.18 __ __ __ __ __Erucastrum pachypodium __ __ 17.3 __ 5.25 __ __ __ __ __ __Guizotia seabra __ __ __ __ __ __ 8.37 __ __ __ __Tribulus terrestris __ __ __ __ __ __ __ __ __ __ 4.86Xanthium spinosus L. 7.3 __ __ __ __ 13.9 __ __ __ __ 30.3Parthenium hysterophorus L. 22.7 102 23.1 31.4 __ 29.2 77.3 74.5 75.9 95.4 __Solanum indicum __ __ __ __ 62.5 __ __ __ __ __ __

Lantana camera L. __ __ __ __ 5.25 __ __ __ 5.52 __ __

Setaria pumila 3.64 __ __ __ 50.5 __ __ __ __ __ __

Cyperus regitidipholus __ __ __ __ __ 11.9 __ __ __ __ __

Argemonne mexicana __ 2.8 __ __ __ __ __ __ __ __ 2.8

In a survey of grazing land and control site, and also on road sides and wet land, it was

found that P. hysterophorus and C. dactylon had a high degree of sociability and these

formed large stands under different habitats. Naithani (1987) observed that Senna uniflora

had a good sociability with P. hysterophorus and that this plant overgrew with P.

hysterophorus in India. In crop field and wet land, O. sinuatum exhibited a high sociability

with P. hysterophorus. The codominance of O.sinuatum was clearly evident in these

sectors.

From the interviews conducted during the study, all of the respondents noticed the impact

of P. hysterophorus on loss of biodiversity. In grazing lands, and roadsides, one can easily

observe the prominent influence of P. hysterophorus on the composition and importance

values of other plant species (Table 10). Haseler (1976) suggested that this may be due to

many factors like wider adaptation across climates, photo insensitivity, and drought

tolerance. Similarly, Krishnamurthy et al. (1997) described the allelopathic nature of P.

hysterophorus and its impact on plant diversity. McFadyen (1992) also reported that P.

hysterophorus is causing a total habitat change in grasslands, open woodlands and

floodplains.

The present study also revealed that P. hysterophorus has become a major pest plant of the

wasteland, road sides crop fields and metropolitan areas of Edo Gojola, Negalign and Elka

Jelmo and it has the potential to spread all over the Woreda. This weed survey of Adami

Tulu-Jido showed a high frequency of P. hysterophorus in general; however, the RF of the

weed in different sectors of the Kebeles ranged from 1.92-19.2% (Appendix 2).

4.2.2 Effects on crop production

About 71.3% farmers who participated in the survey ranked that the infestation of

parthenium weed causes yield reduction, while 15% of the interviewed also indicated

quality deterioration (Table 11). Furthermore, 87.5% of the interviewed farmers concluded

49

that the heavy infestation of parthenium weed leads to intensive labour use for weeding and

hand hoeing and choking irrigation canal thus increasing cost of agricultural production.

Field crops, such as tef (Eragrostis tef), wheat (T. vulgare) and maize (Zea mays) were

found to be the most infested by parthenium weed (Table 12). However, in the surveyed

areas, infestation of parthenium weed in the crop field varied from field to field depending

on the time of its introduction into the area and the efforts made by the farmers to control

the weed by weeding and burning.

Table 11 Farmers’ view on the impacts of Parthenium hysterophorus on crop productivity

Types of impact Frequency (number of responses)

Percent (%)

Yield reduction 114 71.3 Quality reduction 24 15.0 Intensive labour requirement 140 87.5

Increase inputs 6 3.8

Table 12 Plants those resist the impact of P. hysterophorus

Plants most affected by parthenium weed

*Frequency (N) N=160

Percentage of responses (%)

Wheat 101 63.1 Tef 101 63.1 Sorghum 16 10 Maize 11 6.9 Grasses 116 72.5

* N is equal to 160 to all cases

The Woreda is known for the production of maize, sorghum, wheat, tef and other crops;

and also produces different types of vegetables. Moreover, maize, wheat, tef, and sorghum

are used as staple food. Maize is the most dominant crop and used as staple food for an

estimated 89.9% of the population, whereas wheat (56.3%) and tef (54.4%) are used as

both staple food and commercial crops. However, parthenium weed mostly attacks wheat

and tef (63.1%) and to less extent maize and sorghum and beyond that it also attacks fodder

(72.5%). More than 65% of farmers agreed on the effect of P. hysterophorus on crop

production by suppressing growth, yield loss, poor grain fill and by reducing moisture of

50

the soil. P. hysterophorus has also caused change of taste on the food. In India 40%

sorghum yield reduction was reported by Channappagoudar et al. (1990) and Khosla and

Sobti (1981). They also reported that the presence of P. hysterophorus in irrigated sorghum

reduced grain yields from 6.47 to 4.25 tons/ha and decreased grain weight by 30%. In

eastern Ethiopia 40 to 97% sorghum yield reduction was observed due to the impact of P.

hysterophorus (Tamado Tana et al., 2002). However, the exact impact that parthenium

weed is causing on the productivity of crops in economic terms is not well assessed in the

Woreda. Therefore, it needs a daily follow up to quantify the environmental as well as

economic costs due to p. hysterophorus in the Woreda.

4.2.3 Effects on animal production

Since P. hysterophorus was recently introduced weed, its impacts on animal productivity

are not well known and observed. However, its impact was prompted by 30.6% of the

respondent farmers (Table 13). Further 19.1% of the total respondents observed that this

weed has already colonized grazing fields, thus causing fodder/feed scarcity. Evans

(1997a) indicated that the impact of parthenium weed on livestock production is as direct

as indirect by affecting grazing land, animal health, milk and meat quality, and marketing

of pasture seeds and grain. Based on the field survey it was known that parthenium weed is

replacing native grass species (Table 13). Farmers also reported that the milk and meat of

animals grazing on parthenium weed is bitter and tasteless.

In some villages P. hysterophorus could completely dominate grazing land, resulting in a

weed monoculture and reduced stocking rate. In addition, according to farmers, this was

coupled with additional expenses for labour and extensive use of other inputs to control the

parthenium weed infestation.

51

Table 13 Types of effects of P. hysterophorus on livestock production as perceived by

farmers

Types of Effect of Parthenium weed on livestock

Frequency N=160 for all cases

Percentages of responses (%)

Impacts of parthenium on livestock 49 30.6

Reduction of productivity 32 20 Quantity change and reduction 17 10.6 Encroaching grazing lands and suppressing grass species

31 19.1

Effect on livestock health 0 0 Decline families income level 3 1.9

Although, animals usually avoid parthenium weed, it may be consumed in situation where

the weed forms almost pure stands as observed in Edo Gojola, Negalign and Elka Jelemo

Kebeles (Fig 10). Even though there was no report on the deaths of animal due to

parthenium weed in the Woreda, studies in India on the toxicity of the weed to cattle and

buffaloes have shown a significant amount (10-50%) of the weed in the diet can kill these

animals within 30 days (Narasimhan et al., 1977, 1980; More et al., 1982). In Australia,

Chippendale and Panneta (1994) stated that cattle grazing in P. hysterophorus invaded

pastures were marketed with a lower weight compared to those from weed free areas,

accounting for more losses to the producer. Vartak (1968) indicated that the impact of P.

hysterophorus on grasslands could reduce forage production. On the other hand P.

hysterophorus can reduce the carrying capacity of grazing land by up to 90% (Nath, 1988).

Nisar Ahmed et al. (1988) reported that animals fed on P. hysterophorus developed

dermatitis with pronounced skin lesions, became highly emaciated, and eventually died due

to the rupture of tissues and hemorrhages in their internal organs. The impact of P.

hysterophorus on animal health was also reported by Kololgi et al. (1997) where it causes

respiratory disease like bronchitis.

52

4.2.4 Effects on human health

Parthenium hysterophorus is also known to cause human health problems such as asthma,

bronchitis, dermatitis and hay fever in a prolonged contact (Anonymous, 1976; Kologi et

al., 1997; Srirama Rao et al., 1991). The human health problem due to parthenium weed is

not common in the Woreda. However, there are about 18.8% (n=160) cases in the Woreda,

who showed sign of allergy and dermatitis.

There is quite high number of individuals who were also affected by parthenium allergy

and/or dermatitis though it is recently introduced to the Woreda (Appendix 5). However,

the number of individuals who are affected will be increased unless control measure is

taken. About 8.1% of individuals currently exposed to parthenium weed allergy and about

14.4% of individuals also suffer from dermatitis in the study area. Because of the recent

introduction of the parthenium weed in the Woreda, it did not show a heavy health

problem.

Other workers like Anonymous (1976); Srirama Rao et al. (1991); Kololgi et al. (1997) and

Handa et al. (2001) also reported effects of P. hysterophorus on human health like hay

fever, asthma, bronchitis and dermatitis. Evans (1997a) and Towers and Subba Rao (1992)

also reported that close contact with P. hysterophorus could cause allergic contact

dermatitis while inhalation of pollen can cause allergic rhinitis, which can develop into

bronchitis or asthma in susceptible humans. In India, reports of committing suicide are

available due to the chronic problem of P. hysterophorus (Kololgi et al., 1997).

53

5. CONCLUSION AND RECOMMENDATIONS

Conclusion

Parthenium hysterophorus is an invasive alien weed that can be expected to continue its

dissemination because of the negligence of not only farmers but also the local government

to control it. It is growing in farmlands, roadside, grazing lands, wastelands, wetlands and

in towns and villages, gardens. It can germinate and produce seeds throughout the year and

can cause a serious problem in humans, animals and crop production and biodiversity.

This study tried to reveal the farmers’ perception on the impact that can be caused by P.

hysterophorus. Farmers in the study area were aware of P. hysterophorus since 2000,

though its infestation is increasing from year to year. On the other hand, it was apparent

that P. hysterophorus is found densely populated on roadsides, and grazing lands. There

was no much effort done by all responsible bodies including farmers. P. hysterophorus was

observed to grow in any season of the year at different stages, which is at shattering stage,

at flowering and seedling stages. This implies that any intervention intending to control P.

hysterophorus should take into consideration of the ability of P. hysterophorus to grow at

every season of the year.

It was observed that the impact of P. hysterophorus decreases the abundance of plant

species on rangelands, wastelands and road sides. Moreover P. hysterophorus affects

livestock production, productivity, and health including human beings. However, there was

no record from health posts on diseases caused by P. hysterophorus on livestock and

human health. It was concluded that much has not been done to aware the local people on

the danger of P. hysterophorus causing impacts on biodiversity.

Many of the farmers in the study area are aware of that P hysterophorus poses threat for the

loss of biodiversity. The endangered plant species include grasses, forage plants, and

various other species that are economically important for various purposes.

54

Parthenium hysterophorus has become a major pest plant of the grazing land, roadside,

wasteland, wetland as well as cultivated land and it has the potential to cover all over the

Woreda, even beyond the boundary of the Woreda, and threatening the biodiversity of the

Woreda. Rainfall, month of planting, number of weedings, fertilizer use, crop type &

pattern and soil type and/or soil texture were the major environmental/crop management

factors influencing the species distribution in the study area. Maps predicting the severity

of the impact and damage in the Woreda could thus be used to localize areas requiring

interventions most urgently. Recommendations

• Consistent effort should be practiced to control P. hysterophorus till the complete

seed bank is exhausted because of its high and continuous seed production ability

throughout the year.

• However these practices need the integration of the community and responsible

governmental and non-governmental organizations. Further, quarantine measures

should be adopted to check the introduction of weed to non-infested area through

transportation of consumer goods, by movement of livestock and flooding.

• Further study is required to identify the health hazards, impact on biodiversity of P.

hysterophorus, and its management strategy should be developed to control at

national level.

• Joint projects should also be established to prevent and control the danger of P.

hysterophorus at regional level.

• Farmers should be trained both by governmental and non-governmental

organizations on how to prevent and/or control further introduction and

dissemination of the weed.

• Priority Kebeles in the Woreda should be identified based on the prediction map of

current density distribution of P. hysterophorus to act accordingly and to control

further dissemination of P. hysterophorus. Hence, these places are potential sources

for the dissemination of the weed into croplands.

55

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65

7 APPENDICES Appendix 1 parthenium density, altitude and slope in association of GPS reading

Northing (m) Easting(m) Elevation(m)

Current density(per square meter)

Past density(per square meter) Slope (%)

469434 877240 1641 15 3 7 470432 883205 1644 0 0 4 469717 881638 1645 137 10 5 466952 879858 1643 17 5 6 466982 879551 1646 319 43 6 465489 849388 1600 0 0 3 467379 849061 1594 0 0 3 468630 848597 1594 0 0 3 469975 849885 1593 0 0 2 468949 851572 1598 0 0 4 464988 869593 1666 0 0 1 463131 869973 1675 0 0 8 461149 870401 1687 0 0 4 459277 870856 1687 0 0 5 458687 869082 1691 0 0 4 460453 868546 1689 0 0 1 462264 868003 1673 0 0 4 464032 867257 1672 0 0 3 465927 866694 1664 2 0 2 467738 865980 1657 0 0 3 468362 853319 1612 0 0 5 466557 852840 1609 0 0 5 464618 852782 1612 0 0 9 468958 878364 1643 169 41 5 461579 852447 1615 0 0 3 463530 852541 1643 0 0 4 465493 854292 1602 0 0 2 466135 854292 1617 0 0 4 464303 854673 1619 0 0 4 462418 854944 1617 0 0 3 456289 852004 1597 0 0 3 458211 851243 1596 0 0 3 460206 850590 1599 0 0 5 462109 850255 1601 0 0 3 463806 849497 1589 0 0 6 453524 856126 1609 0 0 3 451613 856180 1610 0 0 5 450919 854389 1598 0 0 4 452747 853770 1598 0 0 4 454631 853018 1598 0 0 4 461119 856598 1627 0 0 3 461118 854515 1616 0 0 4 459347 854913 1615 0 0 3 457465 855391 1611 0 0 4

66

455531 855764 1613 0 0 6 467186 864128 1651 0 0 2 465241 864532 1664 10 0 5 470231 873305 1653 10 0 2 463415 865124 1666 0 0 5 461608 865627 1670 0 0 7 459824 866266 1679 0 0 5 457995 866651 1698 0 0 12 457568 864886 1745 0 0 6 459126 864107 1725 0 0 3 460527 863445 1673 0 0 7 452445 860728 1662 0 0 4 454074 859879 1662 0 0 4 455816 859081 1648 0 0 3 457632 858261 1639 0 0 3 459305 857378 1628 0 0 1 462125 862454 1663 0 0 6 463829 861572 1659 0 0 5 462643 860235 1659 0 0 6 469792 875553 1647 103 15 5 462480 860077 1660 0 0 8 460676 860518 1671 0 0 6 458812 860997 1701 0 0 9 456965 861492 1689 0 0 8 455193 861946 1684 0 0 8 453288 862481 1685 0 0 8 465504 871479 1660 0 0 5 467416 870924 1655 4 0 4 469147 870476 1670 0 0 2 468664 868658 1647 1 0 3 466823 869040 1660 18 0 1 465717 878862 1667 0 0 2 467386 878064 1654 30 10 3 468708 877460 1641 63 7 4 468451 875489 1645 135 49 4 471498 888341 1635 109 61 3 469966 887841 1660 20 5 3 467488 888229 1678 0 0 2 465392 889144 1690 0 0 2 470722 886361 1640 50 10 3 470577 885491 1647 100 50 3 470576 885189 1638 0 0 2 469257 885282 1661 0 0 2 467807 885707 1666 0 0 2 467466 884674 1664 0 0 2 468497 884195 1656 0 0 2 469410 884046 1646 0 0 2 466593 879924 1668 0 0 2 464832 880587 1662 0 0 1 463092 881261 1687 0 0 4

67

462058 881460 1713 0 0 9 462325 879909 1729 0 0 10 464035 879425 1680 0 0 5 466749 881910 1668 0 0 4 468789 881207 1646 0 0 5 468995 881150 1641 15 0 2 468977 880166 1640 77 5 1 468467 879391 1643 5 0 1 469539 884827 1650 5 0 2 467645 885038 1667 0 0 3 465812 884898 1677 0 0 1 463826 884965 1684 0 0 2 463335 883206 1687 0 0 3 465068 882571 1675 0 0 4 471012 886825 1645 70 15 5 469460 887744 1662 0 0 4 468323 888888 1685 0 0 1 466561 889280 1690 0 0 2 466308 888461 1680 0 0 3 466294 887635 1681 0 0 1 469978 887556 1660 75 10 3 470043 888881 1662 5 1 6 468316 889291 1683 0 0 1 466739 889687 1692 0 0 2 467127 887707 1679 0 0 3 468746 887189 1662 0 0 1 469755 886664 1662 0 0 3 471008 886604 1640 15 1 12 470523 884991 1643 28 3 4 466693 875699 1659 1 0 9 464790 875829 1668 0 0 6 462995 876077 1683 0 0 4 459988 890153 1738 0 0 3 459823 888394 1729 153 17 3 459290 886691 1740 0 0 10 459007 884786 1749 0 0 6 461158 876412 1706 0 0 4 459296 876719 1734 0 0 5 459125 875077 1695 0 0 2 463132 875113 1692 0 0 3 463184 874937 1671 0 0 1 465372 874847 1662 0 0 1 467324 874633 1651 0 0 3 457253 886904 1761 23 5 2 457766 888697 1765 73 15 1 458182 890461 1770 0 0 6 458502 875586 1716 0 0 13 457980 873782 1712 0 0 7 459791 873180 1696 0 0 6 461742 872524 1687 0 0 4

68

463617 872003 1674 0 0 4 468206 873485 1648 43 10 5 466431 873815 1666 0 0 5 463788 874308 1675 0 0 9 462075 874724 1692 0 0 6 460297 875159 1690 0 0 8

Appendix 2 Frequency of some of the weeds in Adami Tulu-Jido Woreda

0

5

10

15

20

25

Gal

inso

ga

Xan

thiu

m

Oxy

gonu

m

Dig

itaria

vel

utin

a

Dat

ura

Bid

ens

pilo

sa L

.

Cyp

erus

Cyn

odon

Sno

wde

nia

Alte

rnan

ther

a

Com

mel

ina

Eru

cast

rum

Gui

zotia

sea

bra

Trib

ulus

Xan

thiu

m

Par

then

ium

Sol

anum

Lant

ana

cam

era

Set

aria

pum

ila

Cyp

erus

Arg

emon

ne

Appendix 3 Relative Frequency (RF) and Relative Density (RD) of species in different habitats in selected sectors/areas

RF (%) RD (%)

Weeds of selected habitat plot 1

plot 2

plot 3

plot 4

plot 5

plot 6

plot 7

plot 8

plot 9

plot 10

plot 11

Galinsoga pavifolra 7.7 53.5 __ 11.5 __ __ __ 3.23 19.2 __ __ __

Xanthium strumarium 1.92 __ __ __ __ __ __ __ __ __ __

Oxygonium sinuatum 7.7 1.72 __ 23.1 __ __ 30 __ __ __ 1.21 2.94

Digitaria velutina 3.85 17.2 __ __ __ __ __ __ __ __ __ __

Datura stramonium 7.7 5.17 __ 7.69 __ __ 10 __ 2.13 __ __ 17.7

Bidens pilosa 1.92 10.3 __ __ __ __ __ __ __ __ __ __

Cyperus rotundus 7.7 4.42 __ __ __ __ __ 19.2 __ 2.42 __

Cynodon dactylon 13.5 1.72 12.4 11.5 87.8 __ __ 32.3 __ 41.7 20.2 41.2

Snowdenia polystachera 1.92 1.72 __ __ __ __ __ __ __ __ __ 8.82

Alternthera pungens 3.85 1.72 __ 11.5 __ 3.33 __ __ __ __ __ __

Commelina latitalia 1.92 __ __ __ __ 3.33 __ __ __ __ __ __

Erucastrum pachypodium 1.92 __ __ 15.3 __ __ __ __ __ __ __ __

Guizotia seabra 1.92 __ __ __ __ __ __ 6.45 __ __ __ __

Tribulus terrestris 1.92 __ __ __ __ __ __ __ __ __ __ __

Xanthium spinosus 3.85 3.45 __ __ __ __ 10 __ __ __ __ 2.94

Parthenium hysterophorus 19.2 3.45 82.3 3.85 12.2 43.3 10 58.1 55.3 56.7 76.2 26.5

Solanum indicum 1.92 __ __ __ __ 3.33 __ __ __ __ __ __

Lantana camara 3.85 __ __ __ __ 46.7 __ __ __ 1.67 __ __

Setaria pumila 1.92 1.72 __ __ __ __ __ __ __ __ __ __

69

Cyperus regitidipholus 1.92 __ __ __ __ __ 10 __ __ __ __ __

Argemonne mexicana 1.92 __ 0.88 __ __ __ __ __ __ __ __ __

Appendix 4 Questionnaire for data collection to assess perceptions of farmers on the distribution and socio-

economic and environmental impacts of parthenium weed.

Assessing & mapping the Present distribution of parthenium weed in the Adami Tulu-Jido Kombolch

Area, in the central rift valley of Ethiopia

Perception and reactions of farmers on the distribution and impacts of parthenium weed

House Hold Survey Questionnaire No

UTM/Location of HH:

Survey area:

Region Zone Woreda Village

PA __________________

Date of Interview

Name of Interviewer

Name of Head of household____________________ Age _____ Sex______

I. General information about the respondents.

We would like to know the extent of the parthenium weed problems in the village.

1. For how long did you live in this village? (Year)_________________

No Name Age Sex Relationship Education Occupation

1

2

3

Part ІІ: Biophysical and socioeconomic information of P. hysterophorus.

Section A: impact on biodiversity

1. Do you know parthenium weed (P. hysterophorus?) 1. Yes 2. No

2. What is the local name of the P. hysterophorus? __________________________.

3. Since when the parthenium weed seen in this area? __________________.

4. Where did it first appear?

1. Range land 2. Irrigated land 3. Road side 4. Cropland 5. Others (please specify)

_____________________________________________________.

5. How do parthenium weed expanding in your village?

1. Through fodder 2. Through human 3 Through animal 4. Through vehicles 5. others ( please specify ) ______________________________.

6. Is there any soil fertility problem in your farm due to P. hysterophorus?

1. Yes 2. No

7. When did you first realize the problem? (Year)________.

70

8. On which plot?

plot No.

9. What indicators

did you observe?

code a.

10. What management

practices have you

applied to address the

problem? Code b

11. Did you see

any improvement?

Yes ____1

No _____2

Code a: yield decline____2, soil structure and color change____2, decline the composition of vegetation in grazing land_____3, decline income of the family______4, others (please, specify) _____5. Code b: Following 1, crop rotation 2, Intercropping 3, manure 4, Fertilizer

5, mulching 6, Legume trees 7, others (please, specify) _____ 8.

12. Does parthenium weed has ecological importance?

1. Yes, go to question 13 2. No

13. If yes, what are they?

1. Increase fertility of soil

2. Serve us wind break

3. Used as fodder for animals

4. Control soil erosion

5. Others (please, specify)______________________________________.

14. Is there any land which is not invaded by partheinum weed?

1. Yes, go to question no. 31. 2. No

15. If yes, which land use type?

1. Crop land 2. Grazing land 3. Irrigated land 4.Waste land

5.Others (please, specify) ______________________________________________.

16. Why it is not invaded by parthenium?

1. It is far from land which is invaded by parthenium

2. I am removing the weed while it is seedling

3. The crop land is not suitable for the parthenium

4. Cattles are not allowed to go to crop land

5. Others (please, specify) ________________________________________. 17. How much area of land wasted due to parthenium weed in the Woreda? __________.

No Land use Land wasted due to

parthenium weed (%)

Land wasted due to

parthenium weed (ha)

Remark

1 Agricultural land

2 Pasture land

3 Forest /open wood land

4 Wet land /water bodies

5 Industry land

71

6 Others

7 Total area of land wasted

18. Which species dominates the grazing lands?

1. Parthenium weeds 2. Grass 3.Others (please, specify) ______________.

19. What change have you observed in the grazing lands in terms of species composition Cover since the

last 5 years?

1. Natural grass has increased

2. Natural grass has decreased

3. Parthenium weed has increased

4. Parthenium weed has decreased

5. Others (please, specify) _______________________________________.

20. What change have you observed in the grazing lands in terms of species composition Cover since the

last 110 years?






Section B: crop production 1. Is there any weed problem in your farm? 1. Yes, go to question No 2. 2. No 2. on which plot? Plot no.(code a)

3. What is the problem? Code b

4. When did you first observe the parthenium? (year)

5. Did you take any protection measure? Yes___1. No__2

6. When did you start taking these measures? (Year).

7. Did you see any improvement or change after the measure? Yes___1, No_____2

Code a. wheat____1, barley___2, maize___3, sorghum___4, teff___5, grazing land____6, others (please, specify) _____7 Code b. reduction of products___1, reduction of quality____2, increase inputs____3, increase lobour____4, others (please specify) ______5. 8. Is there a decline in land productivity in your farm due to parthenium weed?

1. Yes 2.No 9. How are you ploughing your farm currently?

1. Oxen 2. Hoe 3. Mechanized machines

2 years ago 1. Oxen 2. Hoe 3. Mechanized machines



10. How many times do you plough your farm?

1. Once 2. Twice 3. Three 4. Four 5. Others 11. Do you use fertilizer regularly in your farm? 1. Yes 2. No

72

12. If yes, which type of fertilizer are you using? 1. DAP 2. Urea 3. Manure 4. Others ________________. 13. What is the land cover

currently in your farm? (code

a)

14. What type of

crop you are

producing?

(Code b)

15. On what type

of crop the

parthenium weed

is common?

(Code b)

16. What major impacts

did you observe due to the

presence of parthenium

weed? (Code c)

Code a: grazing____1, farming___2, vegetable and fruits_____3, vegetation_____4, bare land____5, others

(please specify)______6.

Code b: wheat____1, barley___2, maize___3, sorghum___4, teff___5, grazing land____6, others (please,

specify) _____7.

Code c: intensive labour____1, yield reduction____2, health problem____3, others

(please specify) ____4.

17. How foresee the expansion of parthenium weed in this area?

1. Very fast 2. Fast 3. Moderate 4 slow 5. Others __________.

18. What will be the consequences in terms of crop production loss?

___________________________________________________________________.

19. What problems will the invasion of parthenium weed cause to your farm in the coming 5-10 years, if you

do not take any protection measures?

1. Productivity will decline

2. It will increase the cost of inputs

3. It reduces the quality and quantity of cattle production

4. Others (please, specify)

5. I don’t know

20. Was a similar problem?

5 years ago 1.Yes 2.No



21. Do you think that production per unit area has been decline since the last 10 years due to the expansion of

parthenium? 1. Yes 2. No.

22. Is there any income level change since the last 10 years? 1. Yes 2. No

23. If yes, what do think about the causes for declining of income/ output level?

24. The invasion of parthenium weeds in your village and in your farm land

1. Affect the quality of crop and animal outputs

2. Affect the quantity of crop and animal outputs

3. Affect the income level and welfare of the society

73

4. Decline the inflow of tourist into the area

5 Hamper the movement of the people

6. Others (please, specify) ____________________________________________.

25. Which crop type is more important in your family as staple food and economically?

1.Wheat 2. Maize 3. Barley 4. Sorghum 5. Tef 6.Others (please, specify)

Section C: livestock production

1. Is there a grazing land currently in your village?

1. Yes 2.No

2. If No, was there 5 years ago? 1. Yes 2. No

10 years ago 1. Yes 2.No

3. If yes, How much ha (unit)?

4. Which species dominates the grazing lands?

1. Parthenium weeds 2. Grass 3.Others (please, specify) ______________.

5. What change have you observed in the grazing lands in terms of species composition Cover since the last

5 years? 10 years






6. Is there any thing that you used to get and but you lost due to the change in the grazing 1and? 1. Yes

2. No

7. If yes, what are they? ______________________________________________

8. Has the invasion of parthenium weed negatively affected your cattle productivity?

1. Yes 2. No

9. If yes, what are some of these negative impacts?

1. Cattle productivity declines

2. Quality of cattle product declines

3. Declines the income level of the family

4. Take too much labour and time of the family

5. It affects the taste of their products

6. Others (please, specify)._____________________________________________.

10. How much money you lost due to this effects of parthenium on animal productivity?

11. Has the invasion of parthenium weed negatively affected your cattle productivity?

1. Yes 2. No

12. If yes, what are some of these negative impacts?

1. Cattle productivity declines

74

2. Quality of cattle product declines

3. Declines the income level of the family

4. Take too much labour and time of the family

5. It affects the taste of their products

6. Others (please, specify)._____________________________________________.

13. How much money you lost due to this effects of parthenium on animal productivity? ____________

14. Do you think that production per unit area has been decline since the last 10 years due to the expansion of

parthenium? 1. Yes 2. No.

15. Is there any income level change since the last 10 years? 1. Yes 2. No

16. If yes, what do think about the causes for declining of income/ output level? _________________

17. The invasion of parthenium weeds in your village and in your farm land

1. Affect the quality of crop and animal outputs

2. Affect the quantity of crop and animal outputs

3. Affect the income level and welfare of the society

4. Decline the inflow of tourist into the area

5 Hamper the movement of the people

6. Others (please, specify) ____________________________________________.

Section D: health impacts on human and animal

1. Is there any health problem due to the presence of parthenium weed in your village? 1. Yes, go to question

no.50 2. No

2. What is that?

1. Allergy 2.Dermatitis 3.Asthma 4.Others (please, specify) _____________________

3. Did any member of your family got dermatitis?

1. Yes, go to question no51. 2. No

4. Is there any medication to cure the dermatitis?

1. Yes, go to question no. 52 2. No

5. Is there any cultural medication to cure dermatitis? 1. Yes, go to question no53. 2. No

6. Does parthenium weed has any allergy effects. 1. Yes 2.No

Appendix 5 Percentage responses on the impacts of P. hysterophorus on human health

Type of health impacts Frequency (in number)

Percentage (%)

Allergy 13 8.1 Dermatitis 23 14.4

Asthma 3 1.9 The overall impacts due to parthenium

30 18.8

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Appendix 6 Number of plough in which farmers practiced before sawing in the Adami Tulu-Jido, 2007

50.0%

Appendix 7 Parthenium hysterophorus at different growing stages in Adami Tulu-Jido Kombolcha

More than five timesFour timesThree timesTwo times

40.0%

30.0% Percent

20.0% 41.88%

26.88%25.0%

10.0%

6.25%

0.0%

Number of plough

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